Sunset from Western Australia Photo: John Maunder

SunLive - Groundhog Day, February 2, 2021 - The Bay's News First

https://www.sunlive.co.nz/blogs/15244-tauranga-december-rainfalls-18982020.html

https://www.sunlive.co.nz/blogs/15238-in-bleak-midwinter.html

In the Bleak Mid-winter

In the bleak mid-winter,

Frosty wind made moan,

Earth stood hard as iron,

Water like a stone,

Snow had fallen,

Snow on snow,

Snow on snow,

In the bleak mid-winter,

Long ago.

These words, from the first verse of the well-known carol, were written by the English poet Christina Rossetti in 1872 in response to a request from the magazine Scribner's Monthly for a Christmas poem.

It was published posthumously in Rossetti's Poetic Works in 1904. The poem became a Christmas carol after it appeared in The English Hymnal in 1906. The text of this Christmas poem has been set to music many times; the most famous settings being composed by Gustav Holst and Harold Edwin Darke in the early 20th Century. The version by Darke is favoured by cathedral choirs, and is the one usually heard performed on the radio broadcasts of Nine Lessons and Carols by the King's College choir.

The carol featured in the Queen's Christmas TV message in 2012. The carol will also feature on Nine Lessons and Carols by the King's College choir this Christmas Eve, and was also part of the Music and the Spoken Word programme from Mormon Tabernacle Choir on Sunday December 20 on New Zealand’s Prime TV.

Weatherwise, of some significance is that seven years ago on December 15, 2013 the Mail Online (UK) had the following headlines relating to a severe snow storm, which hit the Holy City – and at the same time Cairo experienced its first snowfall in more than 100 years. Perhaps a reminder that Christmas carols really do come alive.

A Christmas card come to Life: Jerusalem hit by worst snowstorm for 20 years, as eight inches fall across Holy City.

- Unusually heavy snowfall, as temperatures dip below freezing.

- Dome of the Rock and Western Wall bathed in white blanket.

- Prime Minister Natanyahu gets in on the fun with family snowball fight.

As all my readers will be aware, the weather is always with us; and although we may all hope that the weather this Christmas and in 2021 will be to our liking, it is perhaps important to remember that in the Southern Hemisphere where the carol In the Bleak Mid-Winter may seem unusual, there have been two significant and tragic events at Christmas.

The first was on Christmas Eve in New Zealand, in 1953, when the Tangiwai rail disaster occurred with loss of 151 lives following a rapid rise in the Tangiwai river. The second was in Darwin, in Australia on Christmas Day 1974, when Tropical Cyclone Tracy killed 71 people and destroyed 80 per cent of the city's houses.

I take this opportunity of wishing all my readers a very happy Christmas and I will be back in 2021 with some more WeatherEyes.

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https://www.sunlive.co.nz/blogs/15214-tauranga-november-average-afternoon-temperatures-19132020.html

Tauranga November Average Afternoon Temperatures 1913-2020

During November 2019, Tauranga had its warmest November ( average afternoon temperature of 23.2 degrees Celsius), since records began in 1913. The average afternoon temperatures in November 2020 was 21.6 degrees C which was the fifth warmest on record.

Temperatures have been recorded in the Tauranga area at several sites in the last 100 years, including the current Tauranga Airport site from June 1990.

The graph shows details of the average daily maximum temperatures (called simply ‘afternoon') for Tauranga for Novembers from 1913-2020.

The long-term average afternoon temperature in November for Tauranga is 20.1 degrees Celsius, ranging from the cool November months of 1976 (18.4 degrees Celsius), and 1941 (18.5 degrees Celsius), to the warm November months of 2013 (22.3 degrees Celsius), and 1954 (22.0 degrees Celsius).

The graph of the average afternoon temperatures for November shows generally normal variations from November to November during the last 100 years, but of note are the five warm Novembers in the years 2010, 2011, 2013, 2019, and 2020.

The average November afternoon temperature during the 50 years from 1963 to 2011 of 20.1 degrees Celsius, is nearly the same as the 20.0 degrees Celsius recorded in the 50 years 1914 to 1961.

From 1913 to 2018, there have been 16 November months with an average afternoon temperature of 21.0 degrees Celsius or more, and seven November months with an average afternoon temperature of less than 19.0 degrees Celsius.

The nine warmest November months (in terms of afternoon temperatures), on record, in chronological order, are 1945, 1954, 1961, 1982, 2010, 2011, 2013, 2019, and 2020.

By contrast, the seventh coolest November months (in terms of afternoon temperatures), on record, in chronological order, are 1918, 1930, 1946, 1968, 1976, 1991, and 1985.

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For further information see my new book Fifteen shades of climate... the fall of the weather dice and the butterfly effect

http://www.sunlive.co.nz/blogs/15172-fifteen-shades-of-climate.html

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https://www.sunlive.co.nz/blogs/15193-tauranga-november-rainfalls-18982020.html

Tauranga November Rainfalls 1898-2020

The second wettest November was 1967, when 240 mm was recorded; the second driest November was in 2011, when only 13 mm fell.

The long-term average rainfall for Tauranga in the month of November is 85 mm. The rainfall for November 2020 was 106 mm.

The graph of the November rainfall shows at first glance normal variations from year to year.

However, there has been a small decrease in the November rainfalls during the last few years.

For example, the average November rainfall in Tauranga for the 50-year period from 1961-2010 of 78 mm is only 85 per cent of the rainfall for the 50-year period 1910-1960.

Since 1898, there have been 11 November months with a rainfall of 150 mm or more (seven of which occurred during the period 1913-1952).

In chronological order, the wettest Novembers are: 1913 with 205 mm, 1916 with 285 mm, 1925 with 167 mm, 1933 with 152 mm, 1936 with 153 mm, 1938 with 174 mm, 1952 with 232 mm, 1967 with 240 mm, 1981 with 191 mm, 1995 with 204 mm, and 1999 with 160 mm.

In terms of dry Novembers, there have been 13 months with rainfall of 30 mm of less, four of which have occurred since 1997.

In chronological order the driest Novembers are 1901 14 mm, 1902 26 mm, 1914 with 17 mm, 1919 with 23 mm, 1928 with 28 mm, 1945 with 20 mm, 1963 with 30 mm, 1982 with 24 mm, 1984 with 19 mm, 1997 with 24 mm, 2009 with 12 mm, 2011 with 13 mm, and 2012 with 27 mm.

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Fifteen shades of climate

During the last few months I have been writing my fifth book.The idea for the book came about when I was visiting my family in Adelaide in January 2020 during a heat wave.

One day when the forecast was for 45°C my daughter Denise suggested I should stay inside, shelter from the heat and write another book.

I asked what did she have in mind and she simply said Climate the Truth.

My son Philip who has lived in Adelaide for about 30 years thought it was a good idea but after a few days thought I settled on a more appropriate title Fifteen shades of climate... the fall of the weather dice and the butterfly effect.

The book is now available through the web site amazon.com. and will be available in New Zealand in mid-December. Just Google “fifteen shades of climate”

www.amazon.com/dp/B08NDR1GFD?ref_=pe_3052080_397514860

Fifteen shades of climate... the fall of the weather dice and the butterfly effect.

The Foreword, the Preface and a list of the Table of Contents are shown below.

From the cover of the book

The explosive nature of the subject climate change during the last three decades, and especially the last few years, when daily and sometimes hourly the words “climate”, “climate change” or “global warming” are mentioned, is well recognised. It has brought about a significant challenge for those of us who are climate scientists to provide details of what is currently happening, why is it happening, and what is going to happen in the next month, year, and decade. An equal challenge is for media, including the social media, to present this information in a coherent manner, so that society, and political leaders at all levels - from the UN down to the local level - make appropriate decisions, whether this involves solar energy, the burning of coal, forest management, hydroelectricity, electric cars, veganism, nuclear power, the building of sea walls, moving to a better climate, learning to live with whatever Nature provides, or even who to vote for in the next election. The media and the education institutes are full (probably overfull) of the “climate story”, but the information portrayed in many cases lacks a full appreciation of the complexity of the climate system. The aim of this book is to “correct” this anomaly. Writing for the non-specialist as well as to the climate community, the book should appeal to graduate classes, not specifically associated with climate, such as history, architecture, political science etc., as well as undergraduate and graduate classes in climate and environmental science. The book should also be of interest to those outside academia such as the media, politicians and the informed public. The author, Dr John Maunder, was President of the Commission for Climatology of the World Meteorological Organization from 1989 to 1997, and has over the last 70 years been involved in the “weather business” in various countries, including New Zealand, Australia, Canada, the USA, Ireland, Switzerland and England, through activities in national weather services, universities and international organizations. Publications include four books: The Value of the Weather (1970), The Uncertainty Business - Risks and Opportunities in Weather and Climate (1986), The Human Impact of Climate Uncertainty - Weather Information, Economic Planning, and Business Management (1989), and the Dictionary of Global Climate Change (1994). Dr Maunder is now retired, living in Tauranga, New Zealand.

The number fifteen in the title relates to the number of chapters in the book but it could more realistically relate to the fifteen or more facets of my eighty years in the “weather business”. These years cover my schooling in New Zealand’s Golden Bay and Nelson College, the University of Otago, employment in the New Zealand Meteorological Service, the University of Otago, the University of Victoria in Canada, the University of Missouri, the World Meteorological Organization, the University of Delaware, the 1985 WMO/ICSU/UNEP Villach Conference, the 1979 WMO First World Climate Conference, the 1990 Second World Climate Conference, the Stockholm Environment Institute, the University College Dublin, the weather business in New Zealand, writing several books, many scientific papers and a host of media releases.

FOREWORD by John Zillman AO FAA FTSE President (1995-2003) of the World Meteorological Organization

There are probably few people in the world who have originated and accumulated as much detailed knowledge of as many different shades of climate as John Maunder. He is a font of wisdom on climate matters and I believe he has served the world extremely well over the past 50 years through the way he has shared that knowledge and wisdom with the global community.

I first met Dr Maunder, when he was Chief of the Agricultural Branch of the World Meteorological Organization (WMO), at the May 1975 WMO Congress in Geneva, and again through his contribution to the proceedings of the December 1975 Monash (Melbourne) Conference on climate change and variability. The WMO Congress commissioned one of the first high-level international expert assessments of climate change and Dr Maunder’s Monash Conference contribution was among the first on the international scene to preview the emerging political and economic dimensions of climate variability and change.

For the next 40 years, Dr Maunder was at the centre of the rapidly advancing international scene on climate data, research, applications and impact studies. This included academic appointments in New Zealand, Canada, the United States and Ireland. When the 1979 WMO Congress established the World Climate Programme (WCP) as an international interdisciplinary framework for understanding and managing climate variability and change, it assigned much of the responsibility for WCP implementation to the WMO Commission for Climatology of which John Maunder was a respected member and future leader.

Through the sixteen years of his Vice Presidency (1981-89) and Presidency (1989-96) of the WMO Commission for Climatology, Dr Maunder guided the international implementation of the ‘data’ and ‘applications’ components of the WCP. As a member of the WMO Executive Committee (now Council) through that period and President of WMO for Dr Maunder’s final two years as President of the Commission, I saw the benefit of his wise and balanced advice to all WMO Member countries across the full range of climate matters. And, as Director of the Australian Bureau of Meteorology at the time, I was particularly pleased when he crossed the Tasman and joined the Bureau as a resident climate expert in 1990-92.

Dr Maunder has always been ahead of the game on climate matters. Before the costs and benefits of the impacts of weather became an issue, he had written a book on ‘The Value of the Weather’. Before the rest of the world had worked out how to use weather and climate information to manage the risks and opportunities of weather and climate variability and extremes, he had captured the essence of the problem with a book on ‘The Uncertainty Business.’ And before the First Report of the Intergovernmental Panel on Climate Change (IPCC) and the 1990 Second World Climate Conference had set in train the negotiation of the United Nations Framework Convention on Climate Change (UNFCCC), he had produced a climate lexicon that became, for many years, the definitive international ‘Dictionary of Global Climate Change.’

While Dr Maunder comes from a meteorological generation for whom the study of climate embraced much more than concern with greenhouse warming and before the venerable scientific field of climatology had been repackaged and narrowed to ‘climate science’, he also became deeply involved in the early study of human-induced climate change. His extensive background in traditional climatology and his participation in the 1985 Villach Conference on the climatic effects of increasing carbon dioxide made him a respected source of wise advice to WMO Member countries when concern with ‘greenhouse warming’ burst upon the world in the 1980s. No-one can keep up with it all but I know of few traditional climatologists who have kept such a careful watch on all aspects of the growing global concern with climate change over the 35 years since Villach. This book is the result and the repository of the accumulated Maunder wisdom of those years.

Dr Maunder sees himself as a ‘realist’ on human-induced climate change. He is troubled by the over-simplification of the climate story and sets out to foster a better public appreciation of the complexity of the climate system. But, while he goes to great lengths to present a wide range of perspectives, including many he disagrees with, he does not refrain from making clear his own views on greenhouse warming or on the many other contentious issues captured in the fifteen shades of climate covered in the fifteen chapters of this book. The issues covered, some quite succinctly but others in great detail, represent almost a complete climate lexicon in their own right and I would be surprised if any reader failed to find at least a few new and illuminating slants on some of the many fascinating different aspects of climate.

This is not a book for those looking for unambiguous scientific support for greenhouse action. But it is, in my view, among the best you could hope to find by way of highly readable and authoritative answers to many of the everyday puzzles of climate. And, for those who have come to the frontiers of climate science without a background in traditional climatology, it contains much distilled wisdom from a generation of progress in a field of study that was once described by the great mathematician John von Neumann, as the most difficult unsolved problem still to confront the scientific intellect of man(sic.

This book also provides a few sobering reminders that, despite the enormous progress of the past fifty years, the von Neumann characterisation may still be close to the mark. I have not always agreed with everything I have found in Dr Maunder’s writing but I have always regarded his books as the epitome of scientific honesty and practical wisdom on climate issues. This book brings it all together. Read any or all of its chapters and you will be wiser on the many fascinating twists of the climate story.

John W Zillman AO FAA FTSE Former Director (1978-2003) of the Australian Bureau of Meteorology Former President (1995-2003) of the World Meteorological Organization

PREFACE

The explosive nature of the “climate” has brought about a significant challenge for those of us who are climate scientists to provide details of what is currently happening, why is it happening, and what is going to happen in the next month, year, and decade. An equal challenge is for media, including the social media, to present this information in a coherent manner, so that society, and political leaders at all levels - from the UN down to the local level, make appropriate decisions, whether this involves solar energy, burning of coal, forest management, hydro electricity, electric cars, veganism, nuclear power, the building of sea walls, moving to a better climate, learning to live with whatever climate Nature provides, or even who to vote for in the next election.

There are many aspects of climate that could be written about, and this book includes most subjects that are commonly discussed in the media, which should be of interest to the public at large. As always there are continual developments in the climate scene and readers may wish to follow the current research by a simple Google search of any topic such as methane, sea level changes, winter temperatures in New Zealand, or an answer to such a question as “Are hurricanes increasing or decreasing in frequency?” The information in this book aims to provide a “need to know” background on weather and climate matters, climate change, and “global warming” with the aim to promote a better understanding of these matters. In my 88 years I have been involved in a wide range of activities in the “climate business”; from watching a river overflow into the small town of Takaka, Golden Bay, New Zealand when I was eight years old and asking why it happened, and was it good or bad; to the realms of several national meteorological services and universities, to the weather business, and the World Meteorological Organization.

Essentially, my book is a collection of specific activities and writings on the questions of climate, climate change, climate’s variability (natural or otherwise) and climate politics over the years. In this regard I am reminded of the physicist Leo Szilard (1898-1964) who once announced to his friend Hans Bethe that he was thinking of keeping a diary: ‘I don’t intend to publish, I am merely going to record the facts for the information of God.’ ‘Don’t you think God knows the facts?’ Bethe asked. ‘Yes’ said Szilard. ‘He knows the facts, but he does not know this version of the facts.’*

Dr. John Maunder

*From Hans Christian von Baeyer, author of “Taming the Atom ”, (from the preface paragraph in “A Short History of Nearly Everything”, by Bill Bryson, A Black Swan Book, 2004).

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Some of the items in my book

Climate change 2020 and the Villach Conference of 1985

Climate overview: The last 400,000 years

The “hockey stick” graph of global warming

Polar bears... increasing or decreasing?

Climate forecasts - how good are they?

Climate change projections for NZ to 2120

Solar activity and spotless days

The Maunder Butterfly

Solar magnetic variations and the Earth’s climate

Gulf Stream - two viewpoints

Southern Annular Mode (SAM)

What are El Niño and La Niña?

Central England temperatures 1700-2018

Global annual temperatures

Arctic and Antarctic Sea Ice

Vikings and their explorations in a warmer world

Building the cathedrals of Europe... the climate factor

An Inconvenient Truth movie

Sea level changes

The year without a summer

Volcanic eruptions

Urban heat island effect

Australian forest fires and climate

Methane 265

Emission Trading Schemes (ETS)

Building sea walls to combat rising sea levels

Declaring Climate Emergencies

Climate refugees

Paying for carbon emissions relating to air travel

Geothermal energy

Nuclear Energy

Tidal Power

Biomass

Intergovernmental Panel on Climate Change (IPCC)

The Paris Climate Agreement

Climate change: three sides of the story

The Kyoto Protocol

Ozone and the 1987 Montreal Protocol

Right and left of climate policies

Green movements around the world and their climate agenda

NIWA’s seven- and eleven-station series

Tauranga annual afternoon temperatures 1913-1919

Tauranga annual rainfalls 1898-2019

Climate extremes in New Zealand

In the bleak mid-winter

Meteorology and philately

Groundhog Day, February 2

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(please include this if there is sufficient space)

TABLE of CONTENTS

Acknowledgements Foreword Preface The fall of the weather dice and the butterfly effect

1 What controls the weather dice? 1 Climate change 2020 and the Villach Conference of 1985 3 Climate change: both sides of the story... a Rotary Conference discussion 5 Ten big climate questions answered 10 Key points about climate change 15 Climate overview: The last 400,000 years 16 Is there an ideal climate? 18

2 Methods of inferring/detecting changes in the climate 25 Recording the weather 27 Homogenization of climate observation and quality control 42 The “hockey stick” graph of global warming 47 Glaciers 50 Ice cores 56 Tree rings 60 West Antarctic Ice Sheet 67 Polar bears... increasing or decreasing? 72

3 Forecasting the climate 75 Weather and Climate Forecasting 77 Blocking Highs 96 Climate forecasts - how good are they? 99 Climate change projections for NZ to 2120 106 Will it be wetter or drier? 111

4 The Sun 119 Solar activity and spotless days 121 The Maunder Minimum 123 The Maunder Butterfly 124 Sunspot numbers 1700 - present 125 Sunspot numbers 1950 - present

5 Astronomical causes of climate change 129 Milanković cycles 131 Solar magnetic variations and the Earth’s climate 142

6 The role of the oceans 145 Global ocean currents as climate controllers 147 Gulf Stream - two viewpoints 154 Indian Ocean Dipole (IOD) 159 Southern Annular Mode (SAM) 163 North Atlantic Oscillation (NAO) 167 What are El Niño and La Niña? 171

7 The climate record over the centuries 175 Central England temperatures 1700-2018 177 Southern Oscillation Index (SOI) 180 Tropospheric temperatures 1979 to May 2020 183 Global temperatures 1996 - May 2020 185 Global annual temperatures 1880 - 2019 187 Arctic and Antarctic temperatures January 1979 to January 2020 190 Arctic and Antarctic Sea Ice 192

8 Lessons from history 195 Vikings and their explorations in a warmer world 197 Building the cathedrals of Europe... the climate factor 203 The Dust Bowl era in the United States in the 1930’s 208 An Inconvenient Truth movie 214 Did global warming take a break? 218 Sea level changes 220

9 Extreme events 223 The year without a summer 225 Volcanic eruptions 228 Tropical Cyclones 232

10 Anthropogenic influences on the climate 243 The Greenhouse effect 245 Urban heat island effect 249 Australian forest fires and climate 255 Methane 265

11 Adaptation to climate 271 Emission Trading Schemes (ETS) 273 Building sea walls to combat rising sea levels 278 Declaring Climate Emergencies 287 Climate refugees 293 Paying for carbon emissions relating to air travel 299

12 Energy 305 Fossil fuels 307 Geothermal energy 311 Nuclear Energy 315 Solar energy 320 Wind power 326 Hydroelectricity 340 Tidal Power 344 Biomass 351 Nuclear fusion 360

13 Official viewpoints 367 Intergovernmental Panel on Climate Change (IPCC) 369 World Climate Programme 387 The Paris Climate Agreement 393 World Meteorological Organization 402 UN Climate Conference 2014 413

14 Political aspects 415 Politics and science 417 Climate change: three sides of the story 418 The Kyoto Protocol 420 Ozone and the 1987 Montreal Protocol 423 Right and left of climate policies 427 Green movements around the world and their climate agenda 432

15 The New Zealand climate over the last 150 years 439 NIWA’s seven- and eleven-station series 441 Tauranga annual average afternoon temperatures 1914-2019 445 Tauranga Average Afternoon Temperatures April 1913-2020 447 Tauranga annual rainfall 1898-2019 449 Tauranga April Rainfalls 1898-2020 451 Climate extremes in New Zealand 453

Annex 455 In the bleak mid-winter 457 Meteorology and philately 459 Groundhog Day, February 2 461 The New Zealand Climate Science Coalition 463 The climate4you.com website 470 New Zealand Chief Scientist’s report 474 Bibliography 476

https://www.sunlive.co.nz/blogs/15160-tropospheric-temperatures-january-1979-to-october-2020.html

Tropospheric Temperatures January 1979 to October 2020

The chart below shows that since 1979, when reliable satellite observations became available, there has been little overall trend in the average tropospheric temperatures, apart from milder/warmer temperatures since about 1997, and two significant warm periods associated with the El Nino events in 1998 and 2015-16.

The latest global average temperatures of the troposphere updated to October 2020 - observed from US National Oceanic and Atmospheric Administration satellites – are computed by the University of Alabama at Huntsville in the United States. The data shows variations from the 30 year period 1981-2010.

Since 1979, NOAA satellites have been carrying instruments which measure the natural microwave thermal emissions from oxygen in the atmosphere. The intensity of the signals these microwave radiometers measure at different microwave frequencies is directly proportional to the temperature of different, deep layers of the atmosphere. Every month, researchers at the University of Alabama (Dr John Christy and Dr Roy Spencer) update global temperature datasets that represent the piecing together of the temperature data from a total of fourteen instruments flying on different satellites over the years.

The graph above represents the latest update; updates are usually made within the first week of every month. Contrary to some reports, the satellite measurements are not calibrated in any way with the global surface-based thermometer records of temperature. They instead use their own on-board precision redundant platinum resistance thermometers calibrated to a laboratory reference standard before launch.

The troposphere is the lowest layer of Earth's atmosphere.

It contains approximately 75 per cent of the atmosphere's mass and 99 per cent of its water vapour and aerosols.

The average depth of the troposphere is approximately 17 km in the middle latitudes.

The latest data for October 2020 is +0.54 degrees C.

The coolest months since 1979 were September 1984, with minus 0.49 degrees Celsius, and November 1984, with minus 0.42 degrees Celsius.

The warmest months were February 2016 with plus 0.83 degrees C, February and April 1998, and February 2020, all plus 0.76 degrees Celsius, and March 2016 plus 0.73 degrees, and April 2016 plus 0.73 degrees Celsius.

The chart shows the El Nino warming in the 1998 period, and 2015-16, and the Mount Pinatubo, volcanic cooling during 1992-1993.

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For further information on a range of weather/climate matters see my just published book.

During the last few months I have been writing my fifth book.The idea for the book came about when I was visiting my family in Adelaide in January 2020 during a heat wave. One day when the forecast was for 45°C my daughter Denise suggested I should stay inside, shelter from the heat and write another book. I asked what did she have in mind and she simply said Climate the Truth. My son Philip who has lived in Adelaide for about 30 years thought it was a good idea but after a few days thought I settled on a more appropriate title Fifteen shades of climate... the fall of the weather dice and the butterfly effect.

The book is now available through the web site amazon.com. Should you or any of your friends/colleagues wish to purchase a copy please go to this web site where my book is shown with the necessary pricing. Please note that if you do not have an account with Amazon.com you will first need to set up an account with Amazon with a password and then you can order my book or anything else from Amazon.

www.amazon.com/dp/B08NDR1GFD?ref_=pe_3052080_397514860

https://www.sunlive.co.nz/blogs/15142-global-temperatures-1996-october-2020.html

Global Temperatures 1996 – October 2020

Global temperatures are compiled for various areas including global (land-ocean), global (meteorological stations), three latitude bands,

and hemispheric, by the Goddard Institute for Space Studies of NASA.

The graph shows the monthly mean global surface temperature anomaly from the base period 1951-1980, for the period 1996-October 2020.

For details see data.giss.nasa. (See graphs at the top right hand corner of the front web page and go to months)

The GISS Surface Temperature Analysis (GISTEMP) is an estimate of global surface temperature change. Graphs and tables are updated around the

middle of every month using current data files from NOAA GHCN v3 (meteorological stations), ERSST v4 (ocean areas), and SCAR (Antarctic stations),

combined as described in our December 2010 publication (Hansen et al. 2010). These updated files incorporate reports for the previous month and

also late reports and corrections for earlier month.

The basic GISS temperature analysis scheme was defined in the late 1970's when a method of estimating global temperature

change was needed for comparison with one-dimensional global climate models. The scheme was based on the finding that the correlation

of temperature change was reasonably strong for stations separated by up to 1200 km, especially at middle and high latitudes. This fact proved

sufficient to obtain useful estimates for global mean temperature changes.

The chart above shows that from 1997 to October 2020 there has been a small warming in the global monthly temperatures, and a relatively

warm period associated with the recent El Nino event.

For further information on a wide range of weather/climate matters. Google:

https://sites.google.com/site/fifteenshadesofclimate2020/

Tauranga October Average Afternoon Temperatures 1913-2020

Temperatures have been recorded in the Tauranga area at several sites in the last 100 years, including the current Tauranga Airport site from June 1990.

The average afternoon temperature for October 2020 for Tauranga was 19.2 degrees C.

The graph shows details of the average daily maximum temperatures (called simply ‘afternoon') for Tauranga for October from 1913-220.

The long-term average afternoon temperature in October for Tauranga is 18.1 degrees Celsius, ranging from the cool October months of 1964 (15.7 degrees Celsius), and 1992 (16.5 degrees Celsius), to the warm October months of 2013 (20.3 degrees Celsius), and 1915 (19.9 degrees Celsius).

The graph of the average afternoon temperatures for October shows generally normal variations from October to October during the last 100 years.

The average October afternoon temperatures during the 50 years from 1963-2011 of 18.0 degrees Celsius is slightly cooler than the 18.3 degrees Celsius recorded in the 50 years from 1914-1961.

From 1913 to 2020, there have been sixteen October months with an average afternoon temperature of 19.0 degrees Celsius or more; and eight October months have had an average afternoon temperature of 17.0 degrees Celsius or less.

The five warmest October months (in terms of afternoon temperatures), on record, in chronological order, are 1913, 1915, 1940, 2013, and 2015.

By contrast, the fifth coolest October months (in terms of afternoon temperatures), on record, in chronological order, are 1941, 1964, 1978, 1982, and 1992.

https://www.sunlive.co.nz/blogs/15118-tauranga-october-rainfalls-18982020.html

Tauranga October Rainfalls 1898-2020

The graph below shows the range of Tauranga's October rainfalls, from an extreme high of 357 mm in 1916 to a low of only 7 mm in 1984.

The second wettest October was 1928, when 269 mm was recorded; and the second driest October was in 1928, when only 11 mm fell.

The long-term average rainfall for Tauranga in the month of October is 110 mm.

The rainfall in October 2020 was 24 mm.

The graph of the October rainfall shows generally normal variations from year to year with some tendency towards drier October months over the years.

Since 1898, there have been 11 October months with a rainfall of 200 mm or more (10 of which occurred during the period 1900-1958), and only one October month since then has recorded this much. Eleven October months have also experienced rainfalls of 25 mm or less.

In chronological order the eleven wettest October months are 1900, 1905, 1916, 1918, 1921, 1926, 1928, 1941, 1952, 1958, and 1983. In contrast the eleventh driest October months are 1906, 1938, 1963, 1965, 1969, 1973, 1984, 1993, 2010, 2013, 2015 and 2020.

For further information see: https://sites.google.com/site/fifteenshadesofclimate2020/

Some details of my new book are on the following webpage.

Google https://sites.google.com/site/fifteenshadesofclimate2020/

Fifteen Shades of Climate ... by John Maunder

The book is currently being considered for publication.

https://www.sunlive.co.nz/blogs/15103-the-southern-oscillation-index1880-2020.html

The Southern Oscillation Index...1880- 2020

The Southern Oscillation Index (SOI) is a standardized index based on the observed sea level pressure differences between Tahiti and Darwin, Australia.

The SOI is a leading measure of the large-scale fluctuations in air pressure occurring between the western and eastern tropical Pacific (i.e., the state of the Southern Oscillation) during El Niño and La Niña episodes.

In general, smoothed time series of the SOI correspond very well with changes in ocean temperatures across the eastern tropical Pacific. The negative phase of the SOI represents below-normal air pressure at Tahiti and above-normal air pressure at Darwin. The positive phase of the SOI represents above-normal air pressure at Tahiti and below-normal air pressure at Darwin.

Prolonged periods of negative SOI values coincide with abnormally warm ocean waters across the eastern tropical Pacific typical of El Niño episodes. In contrast, prolonged periods of positive SOI values coincide with abnormally cold ocean waters across the eastern tropical Pacific typical of La Niña episodes. Sustained negative values of the SOI below −8 often indicate El Niño episodes.These negative values are usually accompanied by sustained warming of the central and eastern tropical Pacific Ocean, a decrease in the strength of the Pacific Trade Winds.

Sustained positive values of the SOI above +8 are typical of a La Niña episode.They are associated with stronger Pacific trade winds and warmer sea temperatures to the north of Australia. Waters in the central and eastern tropical Pacific Ocean become cooler during this time.

The Australian Bureau of Meteorology reports as of October 13 that a La Niña is underway in the tropical Pacific. All surveyed international climate models indicate this La Niña will persist through the southern hemisphere summer 2020–21.

Most models suggest the La Niña will strengthen, peaking in December. Around half the models anticipate a strong event, meaning there is a possibility it could reach similar strength to the La Niña of 2010–12. However, models forecast this event will be shorter, possibly ending in the first quarter of 2021. The strength of La Niña impacts on Australia are often related to the strength of the event.

Central and eastern tropical Pacific Ocean sea surface temperatures remain around La Niña thresholds (0.8 °C below average) and atmospheric indicators, including the Southern Oscillation Index (SOI), trade winds and cloud, are also at La Niña levels.

The graph above ( from the Australian Bureau of Meteorology, BOM) shows monthly values of the SOI from 1880 to September 30, 2020.

The graph above ( from the Australian Bureau of Meteorology, BOM) shows monthly values of the SOI from January 2018 to mid-October 2020.

The 30-day Southern Oscillation Index (SOI) for the 30 days ending mid October 2020 was +6.1.

El Nino and La Nina weather affects over New Zealand (Source Niwa)

During El Niño, New Zealand tends to experience stronger or more frequent winds from the west in summer, typically leading to drought in east coast areas and more rain in the west. In winter, the winds tend to be more from the south, bringing colder conditions to both the land and the surrounding ocean.In spring and autumn south–westerly winds are more common.

La Niña events have different impacts on New Zealand's climate. More north–easterly winds are characteristic, which tend to bring moist, rainy conditions to the north–east of the North Island, and reduced rainfall to the south and south–west of the South Island. Therefore, some areas, such as central Otago and South Canterbury, can experience drought in both El Niño and La Niña. Warmer than normal temperatures typically occur over much of the country during La Niña, although there are regional and seasonal exceptions.

Although ENSO events have an important influence on New Zealand's climate, it accounts for less than 25 per cent of the year to year variance in seasonal rainfall and temperature at most New Zealand measurement sites.

For further information Google https://sites.google.com/site/fifteenshadesofclimate2020/

Fifteen Shades of Climate ... by John Maunder

https://www.sunlive.co.nz/blogs/15085-global-temperatures-1996-september-2020.html

Global Temperatures 1996 – September 2020

Global temperatures are compiled for various areas including global (land-ocean), global (meteorological stations), three latitude bands,

and hemispheric, by the Goddard Institute for Space Studies of NASA.

The graph shows the monthly mean global surface temperature anomaly from the base period 1951-1980, for the period 1996-

September 2020.

For details see data.giss.nasa. (See graphs at the top right hand corner of the front web page and go to months)

The GISS Surface Temperature Analysis (GISTEMP) is an estimate of global surface temperature change. Graphs and tables are updated around the

middle of every month using current data files from NOAA GHCN v3 (meteorological stations), ERSST v4 (ocean areas), and SCAR (Antarctic stations),

combined as described in our December 2010 publication (Hansen et al. 2010). These updated files incorporate reports for the previous month and

also late reports and corrections for earlier month.

The basic GISS temperature analysis scheme was defined in the late 1970's when a method of estimating global temperature

change was needed for comparison with one-dimensional global climate models. The scheme was based on the finding that the correlation

of temperature change was reasonably strong for stations separated by up to 1200 km, especially at middle and high latitudes. This fact proved

sufficient to obtain useful estimates for global mean temperature changes.

The chart above shows that from 1997 to September 2020 there has been a small warming in the global monthly temperatures, and a relatively

warm period associated with the recent El Nino event.

For further information on a wide range of weather/climate matters. Google:

https://sites.google.com/site/fifteenshadesofclimate2020

https://www.sunlive.co.nz/blogs/15067-tauranga-september-average-afternoon-temperatures-19132020.html

Tauranga September Average Afternoon Temperatures 1913-2020

Temperatures have been recorded in the Tauranga area at several sites in the last 100 years, including the current Tauranga Airport site from June 1990.

The graph shows details of the average daily maximum temperatures (simply called “afternoon”) for Tauranga for September from 1913-2020.

The long-term average afternoon temperature in September for Tauranga is 16.6 degrees C, ranging from the “cool” September months of 1964 (14.8 degrees C), and 1977 (14.9 degrees C), to the “warm” September months of 1915 (18.4 degrees C), and 18.3 degrees in 1914.

The afternoon temperature for 2020 was 17.2 degrees C.

The graph of the average afternoon temperatures for September shows generally "normal" variations from September to September during the last 100 years.

From 1913 to 2010, there have been ten September months with an average afternoon temperature of 17.5 degrees C or more, and eight September months with an average afternoon temperature of less than 15.4 degrees C.

The tenth “warmest” September months (in terms of afternoon temperatures) on record, in chronological order, are 1913, 1914, 1915, 1916, 1921, 1926, 1940, 2006, 2009 and 2014.

By contrast, the eighth “coolest” September months (in terms of afternoon temperatures) on record, in chronological order, are 1935, 1964, 1967, 1977, 1992, 1993, 1994 and 1997.

The average afternoon temperature during September for the period 1914-62 was 16.6 degrees, compared with 16.5 degrees from 1963-2011.

For further information see: Google [https:///sites.google.com/site/fifteenshadesofclimate2020/]

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https://www.sunlive.co.nz/blogs/15058-tauranga-september-rainfalls-18982020.html

Tauranga September Rainfalls 1898-2020

Rainfalls for the month of September have been recorded in Tauranga since 1898, except for 1904, 1907, 1908, and 1909.

The graph below shows the range of rainfalls from an extreme high of 274 mm in 1973 to a low of only 16 mm in 1965.

The second wettest September was in 1900, when 256 mm was recorded, and the second driest September was in 1944, when only 27 mm fell. The long-term average rainfall for Tauranga for September is 105 mm.

The graph of the September rainfall shows normal variations from year to year. Since 1898, there have been five Septembers with a rainfall of 200 mm or more (four of which occurred during the period 1900 to 1928, but there's only been one since then), compared with seven September months with a rainfalls of 40 mm or less.

The rainfall for September 2020 was 28 mm which was the third driest September on record .

In chronological order, the ten wettest September months (rainfalls over 180 mm) are 1900,1912,1919,1923,1928,1946,1960,1969,1971,1973, and 2017.

In contrast the thirteenth driest September months (rainfalls of 50 mm or less) are 1910, 1913, 1914, 1921, 1922, 1944, 1965, 1993, 1987, 2006, 2011, 2018 and 2020.

The average rainfall for Tauranga for September for the 50 years 1961-2010 of 103 mm is similar to the rainfall for the previous 50 years (1910-1960).

For further information on a range of weather/climate matters Google https://sites.google.com/site/fifteenshadesofclimate2020/

https://www.sunlive.co.nz/blogs/15043-tropospheric-temperatures-january-1979-to-august-2020.html

Tropospheric Temperatures January 1979 to August 2020

The chart below shows that since 1979, when reliable satellite observations became available, there has been little overall trend in the average tropospheric temperatures, apart from milder/warmer temperatures since about 1997, and two significant warm periods associated with the El Nino events in 1998 and 2015-16.

The latest global average temperatures of the troposphere updated to August 2020 - observed from US National Oceanic and Atmospheric Administration satellites – are computed by the University of Alabama at Huntsville in the United States. The data shows variations from the 30 year period 1981-2010.

Since 1979, NOAA satellites have been carrying instruments which measure the natural microwave thermal emissions from oxygen in the atmosphere.

The intensity of the signals these microwave radiometers measure at different microwave frequencies is directly proportional to the temperature of different, deep layers of the atmosphere.

Every month, researchers at the University of Alabama (Dr John Christy and Dr Roy Spencer) update global temperature datasets that represent the piecing together of the temperature data from a total of fourteen instruments flying on different satellites over the years.

The graph above represents the latest update; updates are usually made within the first week of every month.

Contrary to some reports, the satellite measurements are not calibrated in any way with the global surface-based thermometer records of temperature.

They instead use their own on-board precision redundant platinum resistance thermometers calibrated to a laboratory reference standard before launch.

The troposphere is the lowest layer of Earth's atmosphere.

It contains approximately 75 per cent of the atmosphere's mass and 99 per cent of its water vapour and aerosols.

The average depth of the troposphere is approximately 17 km in the middle latitudes.

The latest data for August 2020 is + 0.43 degrees C.

The coolest months since 1979 were September 1984, with minus 0.49 degrees Celsius, and November 1984, with minus 0.42 degrees Celsius.

The warmest months were February 2016 with plus 0.83 degrees C, February and April 1998, and February 2020, all plus 0.76 degrees Celsius, and March 2016 plus 0.73 degrees, and April 2016 plus 0.73 degrees Celsius.

The chart shows the El Nino warming in the 1998 period, and 2015-16, and the Mount Pinatubo, volcanic cooling during 1992-1993.

For further information on a range of weather/climate matters Google https://sites.google.com/site/fifteenshadesofclimate2020/

https://sunlive.co.nz/blogs/15028-globaltemperatures-1996-august-2020.html

Global Temperatures 1996 – August 2020

The GISS Surface Temperature Analysis (GISTEMP) is an estimate of global surface temperature change. Graphs and tables are updated around the

middle of every month using current data files from NOAA GHCN v3 (meteorological stations), ERSST v4 (ocean areas), and SCAR (Antarctic stations),

combined as described in our December 2010 publication (Hansen et al. 2010). These updated files incorporate reports for the previous month and

also late reports and corrections for earlier month.

The basic GISS temperature analysis scheme was defined in the late 1970's when a method of estimating global temperature

change was needed for comparison with one-dimensional global climate models. The scheme was based on the finding that the correlation

of temperature change was reasonably strong for stations separated by up to 1200 km, especially at middle and high latitudes. This fact proved

sufficient to obtain useful estimates for global ean temperature changes.

The chart above shows that from 1997 to August 2020 there has been a small warming in the global monthly temperatures, and a relatively

warm period associated with the recent El Nino event.

For further information on a wide range of weather/climate matters. Google: https://sites.google.com/site/fifteenshadesofclimate2020/

https://sunlive.co.nz/blogs/15013-the-southern-oscillation-index1880-2020.html

The Southern Oscillation Index...1880- 2020

The Southern Oscillation Index (SOI) is a standardized index based on the observed sea level pressure differences between Tahiti and Darwin, Australia.

The SOI is a leading measure of the large-scale fluctuations in air pressure occurring between the western and eastern tropical Pacific (i.e., the state of the Southern Oscillation) during El Niño and La Niña episodes.

In general, smoothed time series of the SOI correspond very well with changes in ocean temperatures across the eastern tropical Pacific. The negative phase of the SOI represents below-normal air pressure at Tahiti and above-normal air pressure at Darwin. The positive phase of the SOI represents above-normal air pressure at Tahiti and below-normal air pressure at Darwin.

Prolonged periods of negative SOI values coincide with abnormally warm ocean waters across the eastern tropical Pacific typical of El Niño episodes. In contrast, prolonged periods of positive SOI values coincide with abnormally cold ocean waters across the eastern tropical Pacific typical of La Niña episodes. Sustained negative values of the SOI below −8 often indicate El Niño episodes.These negative values are usually accompanied by sustained warming of the central and eastern tropical Pacific Ocean, a decrease in the strength of the Pacific Trade Winds.

Sustained positive values of the SOI above +8 are typical of a La Niña episode.They are associated with stronger Pacific trade winds and warmer sea temperatures to the north of Australia. Waters in the central and eastern tropical Pacific Ocean become cooler during this time.

The graph above ( from the Australian Bureau of Meteorology, BOM) shows monthly values of the SOI from 1880 to May 31, 2020.

The graph above ( from the Australian Bureau of Meteorology, BOM) shows monthly values of the SOI from January 2018 to mid-September 2020..

The 30-day Southern Oscillation Index (SOI) for the 30 days ending late mid-September 2020 was +9.2.

El Nino and La Nina weather affects over New Zealand (Source Niwa)

During El Niño, New Zealand tends to experience stronger or more frequent winds from the west in summer, typically leading to drought in east coast areas and more rain in the west. In winter, the winds tend to be more from the south, bringing colder conditions to both the land and the surrounding ocean.In spring and autumn south–westerly winds are more common.

La Niña events have different impacts on New Zealand's climate. More north–easterly winds are characteristic, which tend to bring moist, rainy conditions to the north–east of the North Island, and reduced rainfall to the south and south–west of the South Island. Therefore, some areas, such as central Otago and South Canterbury, can experience drought in both El Niño and La Niña. Warmer than normal temperatures typically occur over much of the country during La Niña, although there are regional and seasonal exceptions.

Although ENSO events have an important influence on New Zealand's climate, it accounts for less than 25 per cent of the year to year variance in seasonal rainfall and temperature at most New Zealand measurement sites.

For further information Google

For further information Google https://sites.google.com/site/fifteenshadesofclimate2020/

Fifteen Shades of Climate ... by John Maunder

https://sunlive.co.nz/blogs/14998-tauranga-august-rainfalls-18982020.html

Tauranga August Rainfalls 1898-2020

Rainfalls for the month of August have been recorded in Tauranga since 1898, except for 1904, 1907, 1908 and 1909.

From January 1898 to December 1904, the observation site was described as the Tauranga Harbour, from November 1904 to April 1907 the site was described as simply ‘Tauranga'. From January 1910 to December 1923 the site was Waikareao, in Otumoetai; from January 1924 to September 1940 the site was at 148 Waihi Rd, in Judea; from October 1940 to January 1941 the site was at Te Puna; and from February 1941 to now, the site is Tauranga Airport.

The methodology use in adjusting the older sites to the current observing site is published in the ‘NZ Meteorological Service Miscellaneous Publication' No 180 in 1984.

It is considered that the homogeneous rainfall series described here is a fair and true record of what the rainfall would have been if the current observation site (Tauranga Airport) had been used since 1898. This should be coupled with the understanding that although standard accepted methodologies have been used, any adjustments are only estimates of what would have occurred if the location of the rainfall records had always been in the same place with the same surroundings and the same or similar recording gauge.

In terms of climate change (such as is it getting wetter or drier, or warmer or colder), the methodology used in computing an ‘official' set of climate observations is very important, as otherwise erroneous conclusions may be drawn.

The graph shows the range of rainfalls from an extreme high of 274 mm in 2010 to a low of only 17 mm in 1914.

The second wettest August was 1916 when 263 mm was recorded, and the second driest August was in 1982 when only 31 mm fell.

The long-term average rainfall for Tauranga for August is 124 mm. The rainfall for Tauranga for August 2020 was 106 mm.

The graph of the August rainfall shows normal variations from year-to-year.

There is a small decrease in the overall August rainfalls during the last 50 years – from 1961-2010 – from an average of 121 mm, compared with an average of 133 mm during the 50 years from 1911-1960. Since 1898, there have been 11 August months with a rainfall of 220 mm or more – with 10 occurring during 1900 to 1976 – and only one August month since then 2010, which was the highest rainfall for any August. Only five August months have had rainfalls of 50 mm or less.

Chronologically, the 11 wettest August months are 1913, 1916, 1920, 1927, 1938, 1942, 1957, 1965, 1970, 1976 and 2010.

In contrast, chronologically the five driest August months are 1914, 1921, 1982, 1983 and 2002.

*********

For further information Google https://sites.google.com/site/fifteenshadesofclimate2020/

Fifteen Shades of Climate ... by John Maunder

https://sunlive.co.nz/blogs/14986-tauranga-august-average-afternoon-temperatures-19132020.html

Tauranga August Average Afternoon Temperatures 1913-2020

Temperatures have been recorded in the Tauranga area at several sites in the last 107 years, including the current Tauranga Airport site from June 1990.

The graph shows details of the average daily maximum temperatures, called simply ‘afternoon' for Tauranga for August from 1913-2020. The average for August 2020 was 16.1 degrees Celsius.

The long-term average afternoon temperature in August for Tauranga is 14.8 degrees Celsius. The coolest August months have been 1932 with 13.8 degrees Celsius, and 1941 and 1992 recording 13.9 degrees Celsius.

The warm August months have been 2013 with 16.7 degrees Celsius, and 1915 with 16.4 degrees Celsius, while 2009 had 16.2 degrees Celsius, and 2020 had 16.1 degrees.

The graph of the average afternoon temperatures for August shows generally normal variations from August to August during the last 100 years.

But several recent August months have been a little warmer than others since 1913. This includes August 2013, the warmest on record with a temperature of 16.7 degrees Celsius, which was 1.9 degrees Celsius above average.

From 1913 to 2020, there have been 13 August months with an average afternoon temperature of 15.8 degrees Celsius or more.

Thirteen August months have had an average afternoon temperature of less than 14.3 degrees Celsius.

The eighth warmest August months – in terms of afternoon temperatures – on record in chronological order are: 1915, 1967, 1971, 2009, 2012, 2013, 2017, and 2020. By contrast, the fifth coolest August months – in terms of afternoon temperatures – on record, in chronological order are: 1932, 1941, 1966, 1992 and 2004.

The average afternoon temperatures during August for the period 1914-1963 were 14.7 degrees Celsius, compared with 15.0 degrees Celsius from 1964 to 2013.

For further information on a range of weather/climate matters Google climatediceandthebutterfly

https://sunlive.co.nz/blogs/14971-global-temperatures-1996-july-2020.html

Global Temperatures 1996 – July 2020

Global temperatures are compiled for various areas including global (land-ocean), global (meteorological stations), three latitude bands,and hemispheric, by the Goddard Institute for Space Studies of NASA.

The graph shows the monthly mean global surface temperature anomaly from the base period 1951-1980, for the period 1996- July 2020.

For details see data.giss.nasa. (See graphs at the top right hand corner of the front web page and go to months)

The GISS Surface Temperature Analysis (GISTEMP) is an estimate of global surface temperature change. Graphs and tables are updated around the middle of every month using current data files from NOAA GHCN v3 (meteorological stations), ERSST v4 (ocean areas), and SCAR (Antarctic stations),combined as described in our December 2010 publication (Hansen et al. 2010). These updated files incorporate reports for the previous month and also late reports and corrections for earlier month.

The basic GISS temperature analysis scheme was defined in the late 1970's when a method of estimating global temperature change was needed for comparison with one-dimensional global climate models. The scheme was based on the finding that the correlation of temperature change was reasonably strong for stations separated by up to 1200 km, especially at middle and high latitudes.

This fact proved sufficient to obtain useful estimates for global mean temperature changes.

The chart above shows that from 1997 to July 2020 there has been a small warming in the global monthly temperatures, and a relatively warm period associated with the recent El Nino event.

For further information on a wide range of weather/climate matters. Google: climatediceandthebutterfly

https://www.sunlive.co.nz/blogs/14959-tropospheric-temperatures-january-1979-to-july-2020.html

Tropospheric Temperatures January 1979 to July 2020

The chart below shows that since 1979, when reliable satellite observations became available, there has been little overall trend in the average tropospheric temperatures, apart from milder/warmer temperatures since about 1997, and two significant warm periods associated with the El Nino events in 1998 and 2015-16.

The latest global average temperatures of the troposphere updated to July 2020 - observed from US National Oceanic and Atmospheric Administration satellites – are computed by the University of Alabama at Huntsville in the United States. The data shows variations from the 30 year period 1981-2010.

Since 1979, NOAA satellites have been carrying instruments which measure the natural microwave thermal emissions from oxygen in the atmosphere. The intensity of the signals these microwave radiometers measure at different microwave frequencies is directly proportional to the temperature of different, deep layers of the atmosphere. Every month, researchers at the University of Alabama (Dr John Christy and Dr Roy Spencer) update global temperature datasets that represent the piecing together of the temperature data from a total of fourteen instruments flying on different satellites over the years.

The graph above represents the latest update; updates are usually made within the first week of every month. Contrary to some reports, the satellite measurements are not calibrated in any way with the global surface-based thermometer records of temperature. They instead use their own on-board precision redundant platinum resistance thermometers calibrated to a laboratory reference standard before launch.

The troposphere is the lowest layer of Earth's atmosphere.

It contains approximately 75 per cent of the atmosphere's mass and 99 per cent of its water vapour and aerosols.

The average depth of the troposphere is approximately 17 km in the middle latitudes.

The latest data for July 2020 is +0.44 degrees C.

The coolest months since 1979 were September 1984, with minus 0.49 degrees Celsius, and November 1984, with minus 0.42 degrees Celsius.

The warmest months were February 2016 with plus 0.83 degrees C, February and April 1998, and February 2020, all plus 0.76 degrees Celsius, and March 2016 plus 0.73 degrees, and April 2016 plus 0.73 degrees Celsius.

The chart shows the El Nino warming in the 1998 period, and 2015-16, and the Mount Pinatubo, volcanic cooling during 1992-1993.

For further information on a range of weather/climate matters Google Climatediceandthebutterfly

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WeatherEye 387

Tauranga Average July Afternoon Temperatures 1913-2020

The graph below shows details of the average daily maximum temperatures, called ‘afternoon', for Tauranga for July from 1913-2020. The temperature for July 2020 was 14.8 degrees Celsius.

It's very common for areas such as Tauranga to have had different observation sites during the years, and readings from the earlier sites have been adjusted to the present site using standard climatologically procedures.The temperature series described here is a record of what the temperature would have been if the current observation site, Tauranga Airport, had been used throughout the period.

It's important to note, in considering climate change, the methodology used in computing an official set of climate observations is very important as otherwise erroneous conclusions may be drawn.

Traditionally, temperature observations have been recorded with a set of maximum and minimum temperature thermometers.

These record the daily maximum temperature, usually recorded in mid-afternoon, and daily minimum temperature, usually recorded just before dawn.

This analysis of temperatures for Tauranga is for average daily maximum temperatures.

The long-term average afternoon temperature in July for Tauranga is 14.1 degrees Celsius, ranging from cool July months of 1918 and 1939, both 12.3 degrees Celsius, and 1965, with 12.9 degrees Celsius, to the mild July months of 1916, 2010, and 2019 all with 15.8 degrees Celsius, and 1915 with 15.7 degrees Celsius.

The graph of the average afternoon temperatures for July shows generally normal variations from July to July in the last 107 years.

But several July months since 1997 have been a little warmer than average.

From 1913 to 2020, there have been seven July months with an average afternoon temperature of 15.2 degrees Celsius or more, and 11 July months with an average afternoon temperature of less than 13.3 degrees Celsius.

The seventh mildest July months for afternoon temperatures on record, in chronological order are: 1915, 1916, 1917, 1984, 1998, 2000, and 2019.

By contrast, the seven coolest July months for afternoon temperatures on record, in chronological order are: 1918, 1929, 1935, 1939, 1963, 1965, and 1969.

The average afternoon temperature for Tauranga for July for 49 years from 1914-1962 was 14.0 degrees Celsius, compared with the average afternoon temperature for Tauranga for July for 49 years from 1963-2011 was 14.2 degrees Celsius.

For further information on a range of weather and climate matters Google climatediceandthebutterfly

The graph below shows details of the average daily maximum temperatures, called ‘afternoon', for Tauranga for July from 1913-2020. The temperature for July 2020 was 14.8 degrees Celsius.

This analysis of temperatures for Tauranga is for average daily maximum temperatures.

The long-term average afternoon temperature in July for Tauranga is 14.1 degrees Celsius, ranging from cool July months of 1918 and 1939, both 12.3 degrees Celsius, and 1965, with 12.9 degrees Celsius, to the mild July months of 1916, 2010, and 2019 all with 15.8 degrees Celsius, and 1915 with 15.7 degrees Celsius.

The graph of the average afternoon temperatures for July shows generally normal variations from July to July in the last 107 years.

But several July months since 1997 have been a little warmer than average.

From 1913 to 2020, there have been seven July months with an average afternoon temperature of 15.2 degrees Celsius or more, and 11 July months with an average afternoon temperature of less than 13.3 degrees Celsius.

The seventh mildest July months for afternoon temperatures on record, in chronological order are: 1915, 1916, 1917, 1984, 1998, 2000, and 2019.

By contrast, the seven coolest July months for afternoon temperatures on record, in chronological order are: 1918, 1929, 1935, 1939, 1963, 1965, and 1969.

The average afternoon temperature for Tauranga for July for 49 years from 1914-1962 was 14.0 degrees Celsius, compared with the average afternoon temperature for Tauranga for July for 49 years from 1963-2011 was 14.2 degrees Celsius.

For further information on a range of weather and climate matters Google climatediceandthebutterfly

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WEATHEREYE #386

https://www.sunlive.co.nz/blogs/14926-tauranga-july-rainfalls-18982020.html

Tauranga July Rainfalls 1898-2020

Rainfalls for the month of July have been recorded in Tauranga since 1898, except for 1904, 1907, 1908, and 1909.

The graph for the period 1898-2020 shows the range of rainfalls from an extreme high of 348 mm in 1951, to a low of only 2 mm in 1902.

The rainfall for July 2020 was 85 mm. The graph shows the second wettest July was 2012 when 328 mm was recorded, and the second driest July was in 1983 when only 22 mm fell.

The long-term average rainfall for Tauranga for July is 129 mm. The graph of the July rainfall shows ‘normal' variations from year to year.

There is a very small decrease in the overall July rainfalls during the last 50 years (1961-2010) from an average of 127 mm, compared with an average of 132 mm during the 50 years from 1911-1960.

Since 1898, there have been 13 July months with a rainfall of 200 mm or more, but only four July months with rainfalls of 40 mm or less.

The ten wettest July months (in chronological order) have been 1905, 1927, 1938, 1951,1963,1979,1988, 2007, 2008, and 2012. The ten driest July months ( in chronological order) have been 1902, 1918, 1922, 1949, 1969, 1975, 1983, 1997, 2001, and 2010,

For further information on a variety of weather and climate matters Google climatediceandthebutterfly

WEATHEREYE #385

https://www.sunlive.co.nz/blogs/14908-solar-activity-and-next-maunder-minimum.html

Solar Activity and the next Maunder Minimum

The ‘Maunder Minimum' is the name given to the period from 1645 to 1715 when the number of sunspots – ‘storms' on the sun – became almost zero.

The period is named after the solar astronomer Edward Walter Maunder (1851-1928), who was working at The Royal Observatory at Greenwich when he discovered the dearth of sunspots during this period.

During one 30-year period within the Maunder Minimum there were only about 50 sunspots compared with a more typical 40,000. Maunder was a driving force in the foundation of the British Astronomical Association and a Fellow of the Royal Astronomical Society.

The sun was well observed during the period of the Maunder Minimum and this lack of sunspots is well documented. This period of solar inactivity corresponded to a climatic period called the ‘Little Ice Age' when in Europe rivers that were normally ice-free, froze and snow fields remained at low altitudes throughout the year.

There is evidence the sun had similar periods of inactivity during the years 1100-1250 and 1460-1550. Sunspots generally follow a cycle of about 11 years, but cycles have varied from eight-15 years. The connection between solar activity and the earth's climate is an area of ongoing and sometimes controversial research.

An approaching Grand Solar Minimum is gaining “support” including NASA with their recent SC25 prediction — though they stay clear of the implications. NASA’s forecast for the next solar cycle (25) reveals it will be the weakest of the last 200 years.

The maximum of this next cycle — measured in terms of sunspot number, a standard measure of solar activity level — could be 30 to 50% lower than the most recent one. The agency’s results show that the next cycle will start in 2020 and reach its maximum in 2025:

The above chart and the following comment is from NASA’s official website (www.nasa.gov):

The new research was led by Irina Kitiashvili, a researcher with the Bay Area Environmental Research Institute at NASA’s Ames Research Center, in California’s Silicon Valley. It combined observations from two NASA space missions – the Solar and Heliospheric Observatory and the Solar Dynamics Observatory – with data collected since 1976 from the ground-based National Solar Observatory. One challenge for researchers working to predict the Sun’s activities is that scientists don’t yet completely understand the inner workings of our star. Plus, some factors that play out deep inside the Sun cannot be measured directly. They have to be estimated from measurements of related phenomena on the solar surface, like sunspots.

Time will tell whether the sun will once again go into another ‘Maunder Minimum' within the lifetime of the present generation, but if this happens we're likely to have a much colder climate for a few decades.

The sunspot number for most days during the last three months is zero.

A sunspot is a relatively dark, sharply defined region on the solar disc – marked by an umbra, dark area, which is 2000 degrees cooler than the effective photospheric temperature. The average diameter of a sunspot is 4000 km, but they can exceed 200,000 km.

Sunspots are temporary phenomena on the Sun's photosphere that appear as spots darker than the surrounding areas. They are regions of reduced surface temperature caused by concentrations of magnetic field flux that inhibit convection. Sunspots usually appear in pairs of opposite magnetic polarity. Individual sunspots or groups of sunspots may last anywhere from a few days to a few months, but eventually decay.

The NASA solar physics website, and other websites such as the Royal Observatory of Belgium, include information on sunspot numbers, the ‘Maunder Minimum' and sunspot cycle predictions.

The sunspot index is updated monthly and available from 1749. The last time the monthly sunspot number was above 100 during the last 14 years was in September 2002, when the value was 110. February 2014 had a sunspot value of 102.

The last time the value was above 200 was in August 1990, when the value was 200.3..

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For further information on a range of weather.climate matters Google climatediceandthebutterfly

WEATHEREYE #384

https://www.sunlive.co.nz/blogs/14890-tropospheric-temperatures-january-1979-to-june-2020.html

Tropospheric Temperatures January 1979 to June 2020

The chart below shows that since 1979, when reliable satellite observations became available, there has been little overall trend in the average tropospheric temperatures, apart from milder/warmer temperatures since about 1997, and two significant warm periods associated with the El Nino events in 1998 and 2015-16.

The latest global average temperatures of the troposphere updated to June 2020 - observed from US National Oceanic and Atmospheric Administration satellites – are computed by the University of Alabama at Huntsville in the United States. The data shows variations from the 30 year period 1981-2010.

Since 1979, NOAA satellites have been carrying instruments which measure the natural microwave thermal emissions from oxygen in the atmosphere. The intensity of the signals these microwave radiometers measure at different microwave frequencies is directly proportional to the temperature of different, deep layers of the atmosphere. Every month, researchers at the University of Alabama (Dr John Christy and Dr Roy Spencer) update global temperature datasets that represent the piecing together of the temperature data from a total of fourteen instruments flying on different satellites over the years.

The graph above represents the latest update; updates are usually made within the first week of every month. Contrary to some reports, the satellite measurements are not calibrated in any way with the global surface-based thermometer records of temperature. They instead use their own on-board precision redundant platinum resistance thermometers calibrated to a laboratory reference standard before launch.

The troposphere is the lowest layer of Earth's atmosphere.

It contains approximately 75 per cent of the atmosphere's mass and 99 per cent of its water vapour and aerosols.

The average depth of the troposphere is approximately 17 km in the middle latitudes.

The latest data for June 2020 is +0.43 degrees C.

The coolest months since 1979 were September 1984, with minus 0.49 degrees Celsius, and November 1984, with minus 0.42 degrees Celsius.

The warmest months were February 2016 with plus 0.83 degrees C, February and April 1998, and February 2020, all plus 0.76 degrees Celsius, and March 2016 plus 0.73 degrees, and April 2016 plus 0.73 degrees Celsius.

The chart shows the El Nino warming in the 1998 period, and 2015-16, and the Mount Pinatubo, volcanic cooling during 1992-1993.

For further information on a range of weather/climate matters Google Climatediceandthebutterfly

WeatherEye 384

https://www.sunlive.co.nz/blogs/14875-tauranga-june-average-afternoon-temperatures-19132020.html

Tauranga June Average Afternoon Temperatures 1913-2020

Temperatures have been recorded in the Tauranga area at several sites during the last 108 years, including at the current Tauranga Airport site from June 1990.

The graph shows details of the average daily maximum temperatures, called simply ‘afternoon', for Tauranga for June from 1913-2020.

The long-term average afternoon temperature in June for Tauranga is 14.8 degrees Celsius.

The cool' June months were in 1972 with 13.0 degrees Celsius, 1936 with 13.2 degrees Celsius, and 1933 with 13.3 degrees Celsius.

The ‘warm' June months were in 2014 with 16.9 degrees Celsius, 1916 and 2011 and 2020, all with 16.6 degrees Celsius, and June 2016 with 16.5 degrees C.

June 2020 had an average afternoon temperature of 16.6 degrees Celsius which was the third equal warmest June on record since observations were first made in 1913.

The graph of the average afternoon temperatures for June shows generally ‘normal' variations from June to June during the last 100 years.

But many of the last 20 June months since 1996 have been a little ‘warmer' than other June months since 1913.

From 1913 to 2020, there have been 16 June months with an average afternoon temperature of 15.6 degrees Celsius or more, and 12 June months with an average afternoon temperature of less than 13.9 degrees Celsius.

The eleventh ‘warmest' June months on record, in chronological order, are: 1916, 1971, 1981, 1998, 1999, 2002, 2003, 2011, 2014, 2016 and 2020.

By contrast, the seventh ‘coolest' June months on record, in chronological order, are 1933, 1936, 1941, 1944,1969, 1972 and 1976.

The average afternoon temperature in June during the period 1914-1962 was 14.7 degrees Celsius compared with 14.8 degrees Celsius from 1963 to 2011.

For further information Google climatediceandthebutterfly

WeatherEye 382

https://www.sunlive.co.nz/blogs/14863-tauranga-june-rainfalls-18982020.html

Tauranga June Rainfalls 1898-2020

Monthly rainfalls for Tauranga have been recorded at several recording sites during the last 122 years.

From January 1898 to December 1904, the observation site was described as the Tauranga Harbour, from November 1904 to April 1907 the site was described as simply ‘Tauranga'.From January 1910 to December 1923 the site was Waikareao, in Otumoetai; from January 1924 to September 1940 the site was at 148 Waihi Rd, in Judea; from October 1940 to January 1941 the site was at Te Puna; and from February 1941 to now, the site is Tauranga Airport.

The methodology use in adjusting the older sites to the current observing site is published in the ‘NZ Meteorological Service Miscellaneous Publication' No 180 in 1984.

It is considered that the homogeneous rainfall series described here is a fair and true record of what the rainfall would have been if the current observation site (Tauranga Airport) had been used since 1898.

This should be coupled with the understanding that although standard accepted methodologies have been used, any adjustments are only estimates of what would have occurred if the location of the rainfall records had always been in the same place with the same surroundings and the same or similar recording gauge.

In terms of climate change (such as is it getting wetter or drier, or warmer or colder), the methodology used in computing an ‘official’ set of climate observations is very important, as otherwise erroneous conclusions may be drawn.

The graph shows the range of rainfalls from an extreme high of 381 mm in 1925 to a low of 19 mm in 1906.

The rainfall in June 2020 was 262 mm, the fourth wettest June in 122 years of observations.

Since 1898, there have been 18 June months with a rainfall of 200 mm or more, and 11 June months with rainfalls of 50 mm or less.

In chronological order the wettest 18 June months are: 1915, 1917, 1920, 1925, 1930, 1935, 1939, 1943, 1946, 1961, 1968, 1971, 1981, 1985, 1997, 2010, 2014 and 2020.

By contrast the driest June months in chronological order are: 1906, 1913, 1914, 1933, 1942, 1958, 1959, 1967, 2001, 2012, and 2015.

For further information on range of climate matters see Google: climatediceandthebutterfly

WeatherEye 381

https://www.sunlive.co.nz/blogs/14844-te-southern-oscillation-index1880-2020.html

The Southern Oscillation Index...1880- 2020

The Southern Oscillation Index (SOI) is a standardized index based on the observed sea level pressure differences between Tahiti and Darwin, Australia.

The SOI is a leading measure of the large-scale fluctuations in air pressure occurring between the western and eastern tropical Pacific (i.e., the state of the Southern Oscillation) during El Niño and La Niña episodes.

In general, smoothed time series of the SOI correspond very well with changes in ocean temperatures across the eastern tropical Pacific. The negative phase of the SOI represents below-normal air pressure at Tahiti and above-normal air pressure at Darwin. The positive phase of the SOI represents above-normal air pressure at Tahiti and below-normal air pressure at Darwin.

Prolonged periods of negative SOI values coincide with abnormally warm ocean waters across the eastern tropical Pacific typical of El Niño episodes. In contrast, prolonged periods of positive SOI values coincide with abnormally cold ocean waters across the eastern tropical Pacific typical of La Niña episodes. Sustained negative values of the SOI below −8 often indicate El Niño episodes.These negative values are usually accompanied by sustained warming of the central and eastern tropical Pacific Ocean, a decrease in the strength of the Pacific Trade Winds.

Sustained positive values of the SOI above +8 are typical of a La Niña episode.They are associated with stronger Pacific trade winds and warmer sea temperatures to the north of Australia. Waters in the central and eastern tropical Pacific Ocean become cooler during this time.

The graph above ( from the Australian Bureau of Meteorology, BOM) shows monthly values of the SOI from 1880 to May 31, 2020.

The graph above ( from the Australian Bureau of Meteorology, BOM) shows monthly values of the SOI from January 2018 to late June 2020.

The 30-day Southern Oscillation Index (SOI) for the 30 days ending late June 2020 was –9.2.

El Nino and La Nina weather affects over New Zealand (Source Niwa)

During El Niño, New Zealand tends to experience stronger or more frequent winds from the west in summer, typically leading to drought in east coast areas and more rain in the west. In winter, the winds tend to be more from the south, bringing colder conditions to both the land and the surrounding ocean.In spring and autumn south–westerly winds are more common.

La Niña events have different impacts on New Zealand's climate. More north–easterly winds are characteristic, which tend to bring moist, rainy conditions to the north–east of the North Island, and reduced rainfall to the south and south–west of the South Island. Therefore, some areas, such as central Otago and South Canterbury, can experience drought in both El Niño and La Niña. Warmer than normal temperatures typically occur over much of the country during La Niña, although there are regional and seasonal exceptions.

Although ENSO events have an important influence on New Zealand's climate, it accounts for less than 25 per cent of the year to year variance in seasonal rainfall and temperature at most New Zealand measurement sites.

For further information Google climatediceandthebutterfly

WeatherEye 380

https://www.sunlive.co.nz/blogs/14820-global-temperatures-1996-may-2020.html

Global Temperatures 1996 – May 2020

Global temperatures are compiled for various areas including global (land-ocean), global (meteorological stations), three latitude bands,

and hemispheric, by the Goddard Institute for Space Studies of NASA.

The graph shows the monthly mean global surface temperature anomaly from the base period 1951-1980, for the period 1996- May 2020.

For details see data.giss.nasa. (See graphs at the top right hand corner of the front web page and go to months)

The GISS Surface Temperature Analysis (GISTEMP) is an estimate of global surface temperature change. Graphs and tables are updated around the

middle of every month using current data files from NOAA GHCN v3 (meteorological stations), ERSST v4 (ocean areas), and SCAR (Antarctic stations),

combined as described in our December 2010 publication (Hansen et al. 2010). These updated files incorporate reports for the previous month and

also late reports and corrections for earlier month.

The basic GISS temperature analysis scheme was defined in the late 1970's when a method of estimating global temperature

change was needed for comparison with one-dimensional global climate models. The scheme was based on the finding that the correlation

of temperature change was reasonably strong for stations separated by up to 1200 km, especially at middle and high latitudes. This fact proved

sufficient to obtain useful estimates for global mean temperature changes.

The chart above shows that from 1997 to May 2020 there has been a small warming in the global monthly temperatures, and a relatively

warm period associated with the recent El Nino event.

For further information on a wide range of weather/climate matters. Google: climatediceandtheweatherdice

WeatherEye 379

https://www.sunlive.co.nz/blogs/14796-tropospheric-temperatures-january-1979-to-may-2020.html

Tropospheric Temperatures January 1979 to May 2020

The chart below shows that since 1979, when reliable satellite observations became available, there has been little overall trend in the average tropospheric temperatures, apart from milder/warmer temperatures since about 1997, and two significant warm periods associated with the El Nino events in 1998 and 2015-16.

The latest global average temperatures of the troposphere updated to May 2020 - observed from US National Oceanic and Atmospheric Administration satellites – are computed by the University of Alabama at Huntsville in the United States. The data shows variations from the 30 year period 1981-2010.

Since 1979, NOAA satellites have been carrying instruments which measure the natural microwave thermal emissions from oxygen in the atmosphere. The intensity of the signals these microwave radiometers measure at different microwave frequencies is directly proportional to the temperature of different, deep layers of the atmosphere. Every month, researchers at the University of Alabama (Dr John Christy and Dr Roy Spencer) update global temperature datasets that represent the piecing together of the temperature data from a total of fourteen instruments flying on different satellites over the years.

The graph above represents the latest update; updates are usually made within the first week of every month. Contrary to some reports, the satellite measurements are not calibrated in any way with the global surface-based thermometer records of temperature. They instead use their own on-board precision redundant platinum resistance thermometers calibrated to a laboratory reference standard before launch.

The troposphere is the lowest layer of Earth's atmosphere.

It contains approximately 75 per cent of the atmosphere's mass and 99 per cent of its water vapour and aerosols.

The average depth of the troposphere is approximately 17 km in the middle latitudes.

The latest data for May is +0.54 degrees C.

The coolest months since 1979 were September 1984, with minus 0.49 degrees Celsius, and November 1984, with minus 0.42 degrees Celsius.

The warmest months were February 2016 with plus 0.83 degrees C, February and April 1998, and February 2020, all plus 0.76 degrees Celsius, and March 2016 plus 0.73 degrees, and April 2016 plus 0.73 degrees Celsius.

The chart shows the El Nino warming in the 1998 period, and 2015-16, and the Mount Pinatubo, volcanic cooling during 1992-1993.

For further information on a range of weather/climate matters Google Climatediceandthebutterfly

WeatherEye 378

https://www.sunlive.co.nz/blogs/14764-tauranga-average-afternoon-temperatures-may-2020.html

Tauranga average afternoon temperatures May 2020

The average afternoon temperature in Tauranga in May 2020 was 18.2 degrees C.

Temperatures have been recorded in the Tauranga area at several sites during the last 100 years, including the current Tauranga Airport site from June 1990.

It's very common for areas, such as Tauranga, to have experienced different observation sites during the years – and the readings from the earlier sites have been adjusted to the present site using standard climatological procedures.

It's considered the temperature series described here is a fair and true record of what the temperature would have been if the current observation site (of Tauranga Airport) had been used throughout the period.

Traditionally, temperature observations have been recorded with a set of maximum and minimum temperature thermometers.

These record the daily maximum temperature – usually recorded in mid-afternoon – and daily minimum temperature – usually recorded just before dawn.

This analysis of temperatures for Tauranga is for the average daily maximum temperatures.

The graph shows details of the average daily maximum temperatures, called simply ‘afternoon', for Tauranga for May from 1913-2020. May 1964 is not included because of incomplete data.

The long-term average afternoon temperature in May for Tauranga is 16.9 degrees Celsius, ranging from the cool May months of 1936, 1940, and 1997 with an average afternoon temperature of 14.9 degrees Celsius, to the warm May months of 1916 and 2016 both with an average afternoon temperature of 19.3 degrees Celsius, May 2011 with 19.1 degrees Celsius, and May 2007 with 18.9 degrees Celsius.

The graph of the average afternoon temperatures for May shows generally normal variations from May to May.

However, the last 20 May months have been a little warmer than other May months since 1913.

From 1913 to 2020, there have been 16 May months with an average afternoon temperature of 18 degrees Celsius or more, and 11 May months with an average afternoon temperature of less than 16 degrees Celsius.

The 16 warmest May months, in terms of afternoon temperatures, on record in chronological order are: 1916, 1928, 1938, 1950, 1999, 2000, 2003, 2005, 2007, 2010, 2011, 2013, 2014, 2016, 2019 and 2020.

In contrast, the 11 coolest May months, in terms of afternoon temperatures, on record in chronological order are: 1913, 1920, 1924, 1936, 1940, 1945, 1959, 1967, 1977, 1983, and 1992.

The average afternoon temperature in May during the 49-year period 1914-1962 was 16.7 degrees Celsius, compared with 17.1 degrees Celsius for the 49-year period from 1963-2011.

For further information: Google climatediceandthebutterfly

WEATHEREYE #377

https://www.sunlive.co.nz/blogs/14744-may-rainfalls-tauranga-18982020.html

May Rainfalls for Tauranga 1898-2020

Rainfalls for the month of May have been recorded in Tauranga since 1898 – except for 1904, 1907, 1908, and 1909.

The graph shows the range of rainfalls from an extreme high of 634 mm in 2005 to a low of 13 mm in 2001. The rainfall for May 2020 was 57 mm.

The total rainfall in Tauranga for the first five months of 2020 of 144 mm is lowest on record since records began in 1898.

The second wettest May was 1950, when 311 mm was recorded, and the second driest May was in 1918, when only 24 mm fell. The long-term average rainfall for Tauranga for May is 124 mm.

Apart from the exceptional rainfall of 634 mm in May 2005, the graph shows a small decrease in overall May rainfalls when the last two 50-year periods are compared.

Since 1898, there have been 14 May months with a rainfall of 200 mm or more. In chronological order, the wettest May months are: 1899, 1900, 1917, 1925, 1926, 1928, 1949, 1950, 1956, 1961, 1962, 1971, 2005, and 2010.

In terms of dry May months, there have been only nine May months with rainfall of less than 40 mm. In chronological order, the driest May months are: 1901, 1918, 1939, 1941, 1978, 1991, 1999, 2007, and 2014.

Of particular significance is the exceptional rainfall in May 2005. I estimated that such a rainfall is likely to occur in Tauranga only about twice in every 1000 years. This suggests central government could have had a much more important role in financial implications of the floods, which affected many areas of Tauranga in May 2005.

For further information on the rainfalls in Tauranga Google climatediceandthebutterfly

WeatherEye 376

Tropospheric Temperatures 1979 to April 2020

The chart below shows that since 1979, when reliable satellite observations became available, there has been little overall trend in the average tropospheric temperatures, apart from milder/warmer temperatures since about 1997, and two significant warm periods associated with the El Nino events in 1998 and 2015-16.

The latest global average temperatures of the troposphere updated to April 2020 observed from US National Oceanic and Atmospheric Administration satellites – are computed by the University of Alabama at Huntsville in the United States. The data shows variations from the 30 year period 1981-2010.

Since 1979, NOAA satellites have been carrying instruments which measure the natural microwave thermal emissions from oxygen in the atmosphere. The intensity of the signals these microwave radiometers measure at different microwave frequencies is directly proportional to the temperature of different, deep layers of the atmosphere. Every month, researchers at the University of Alabama (Dr John Christy and Dr Roy Spencer) update global temperature datasets that represent the piecing together of the temperature data from a total of fourteen instruments flying on different satellites over the years.

The graph above represents the latest update; updates are usually made within the first week of every month. Contrary to some reports, the satellite measurements are not calibrated in any way with the global surface-based thermometer records of temperature. They instead use their own on-board precision redundant platinum resistance thermometers calibrated to a laboratory reference standard before launch.

The troposphere is the lowest layer of Earth's atmosphere.

It contains approximately 75 per cent of the atmosphere's mass and 99 per cent of its water vapour and aerosols.

The average depth of the troposphere is approximately 17 km in the middle latitudes.

The latest data for April 2020 is +0.38 degrees C.

The coolest months since 1979 were September 1984, with minus 0.49 degrees Celsius, and November 1984, with minus 0.42 degrees Celsius.

The warmest months were February 2016 with plus 0.83 degrees C, February and April 1998, and February 2020, all plus 0.76 degrees Celsius, and March 2016 plus 0.73 degrees, and April 2016 plus 0.73 degrees Celsius.

The chart shows the El Nino warming in the 1998 period, and 2015-16, and the Mount Pinatubo, volcanic cooling during 1992-1993.

For further information on a range of weather/climate matters Google Climatediceandthebutterfly

WeatherEye 375

The Southern Oscillation Index

The Southern Oscillation Index (SOI) is a standardized index based on the observed sea level pressure differences between Tahiti and Darwin, Australia.

The SOI is a leading measure of the large-scale fluctuations in air pressure occurring between the western and eastern tropical Pacific (i.e., the state of the Southern Oscillation) during El Niño and La Niña episodes.

In general, smoothed time series of the SOI correspond very well with changes in ocean temperatures across the eastern tropical Pacific. The negative phase of the SOI represents below-normal air pressure at Tahiti and above-normal air pressure at Darwin. The positive phase of the SOI represents above-normal air pressure at Tahiti and below-normal air pressure at Darwin.

Prolonged periods of negative SOI values coincide with abnormally warm ocean waters across the eastern tropical Pacific typical of El Niño episodes. In contrast, prolonged periods of positive SOI values coincide with abnormally cold ocean waters across the eastern tropical Pacific typical of La Niña episodes. Sustained negative values of the SOI below −8 often indicate El Niño episodes.These negative values are usually accompanied by sustained warming of the central and eastern tropical Pacific Ocean, a decrease in the strength of the Pacific Trade Winds.

Sustained positive values of the SOI above +8 are typical of a La Niña episode.They are associated with stronger Pacific trade winds and warmer sea temperatures to the north of Australia. Waters in the central and eastern tropical Pacific Ocean become cooler during this time.

The graph below ( from the Australian Bureau of Meteorology, BOM) shows monthly values of the SOI from 1880 to May 2020.

The 30-day Southern Oscillation Index (SOI) for the 30 days ending mid-May was +1.6.

El Nino and La Nina weather affects over New Zealand (Source Niwa)

During El Niño, New Zealand tends to experience stronger or more frequent winds from the west in summer, typically leading to drought in east coast areas and more rain in the west.

In winter, the winds tend to be more from the south, bringing colder conditions to both the land and the surrounding ocean.

In spring and autumn south–westerly winds are more common.

La Niña events have different impacts on New Zealand's climate. More north–easterly winds are characteristic, which tend to bring moist, rainy conditions to the north–east of the North Island, and reduced rainfall to the south and south–west of the South Island.

Therefore, some areas, such as central Otago and South Canterbury, can experience drought in both El Niño and La Niña.

Warmer than normal temperatures typically occur over much of the country during La Niña, although there are regional and seasonal exceptions.

Although ENSO events have an important influence on New Zealand's climate, it accounts for less than 25 per cent of the year to year variance in seasonal rainfall and temperature at most New Zealand measurement sites.

For further information Google climatediceandthebutterfly

WeatherEye 374

https://www.sunlive.co.nz/blogs/14668-tauranga-average-afternoon-temperatures-april-19132020.html

Tauranga Average Afternoon Temperatures April 1913-2020

Temperatures have been recorded in the Tauranga area at several sites during the last 100 years, including the current Tauranga Airport site from June 1990.

It's very common for areas such as Tauranga to have had different observation sites during the years – and the readings from the earlier sites have been adjusted to the present site using standard climatologically procedures.

The temperature series, as shown in the graph, are based on the data from the original observations from the various sites as available on the NIWA National Climate Database archive, with data from the sites prior to the Tauranga Airport site being adjusted, where appropriate, to temperatures which are likely to have been recorded at the current airport site.

Traditionally, temperature observations have been recorded with a set of maximum and minimum temperature thermometers.

These record the daily maximum temperature (usually recorded in mid-afternoon), and the daily minimum temperature (usually recorded just before dawn).

The graph shows details of the average daily maximum temperatures (called simply ‘afternoon'), for Tauranga for April from 1913-2020. Note April 1947 and 1964 are not included because of incomplete data.

The long-term average afternoon temperature in April for Tauranga for is 20.0 degrees Celsius, ranging from the cool April months of 1925, with an average afternoon temperature of 18.2 degrees Celsius, and 1923 with an average afternoon temperature of 18.3 degrees Celsius, to the warm April months of 1938 (22.2 degrees Celsius), and 1916 (22.1 degrees Celsius).

The graph of the average afternoon temperatures for April shows generally normal variations from April to April, but several recent April months have been a little warmer than other April months.

From 1913 to 2020, there have been 15 April months with an average afternoon temperature of 21.0 degrees Celsius or more, and eight April months with an average afternoon temperature of less than 19.0 degrees Celsius.

The value for April 2019 was 20.9 degrees Celsius,

The 15 warmest April months – in terms of afternoon temperatures – on record, in chronological order, are 1916, 1924, 1928, 1935, 1938, 1948, 1955, 1956, 1978, 1981, 2010, 2012, 2013, 2014, and 2016. In contrast, the eight coolest April months – in terms of afternoon temperatures – on record, in chronological order, are 1923, 1925, 1940, 1941, 1949, 1980, 1991 and 1992.

The average afternoon temperatures for Tauranga for the 50 years 1914-1962, and the 50-year period 1963-2011 are both 20.0 degrees Celsius

For further information Google: climatediceandthebutterfly

WeatherEye 373

https://www.sunlive.co.nz/blogs/14636-tauranga-april-rainfalls-18982020.html

Tauranga April Rainfalls 1898-2020

Monthly rainfalls for Tauranga have been recorded at several recording sites during the last 122 years.

From January 1898 to December 1904, the observation site was described as the Tauranga Harbour, from November 1904 to April 1907 the site was described as simply ‘Tauranga'.From January 1910 to December 1923 the site was Waikareao, in Otumoetai; from January 1924 to September 1940 the site was at 148 Waihi Rd, in Judea; from October 1940 to January 1941 the site was at Te Puna; and from February 1941 to now, the site is Tauranga Airport.

The methodology use in adjusting the older sites to the current observing site is published in the ‘NZ Meteorological Service Miscellaneous Publication' No 180 in 1984.

It is considered that the homogeneous rainfall series described here is a fair and true record of what the rainfall would have been if the current observation site (Tauranga Airport) had been used since 1898.

This should be coupled with the understanding that although standard accepted methodologies have been used, any adjustments are only estimates of what would have occurred if the location of the rainfall records had always been in the same place with the same surroundings and the same or similar recording gauge.

In terms of climate change (such as is it getting wetter or drier, or warmer or colder), the methodology used in computing an ‘official' set of climate observations is very important, as otherwise erroneous conclusions may be drawn.

April 2020 had a rainfall of 16 mm.

The total rainfall for the fours months January to April 2020 of 87 mm was the lowest rainfall for the January to April period since observation began in 1898.

The graph shows the range of rainfalls from a high of 383 mm in 1911 to a low of 10 mm in 1958.

The second wettest April was 1948, when 333 mm was recorded; and the second driest was April 2010 with only 12 mm.

The long-term average rainfall for Tauranga for April is 120 mm.

Since 1898, there have been 11 April months with a rainfall of 250 mm or more.

In chronological order, the wettest April months are: 1911, 1923, 1935, 1938, 1948, 1959, 1995, 2000, 2001, 2013, and 2017.

In terms of dry April months, there have been ten months with rainfall of 30 mm or less.

In chronological order, the driest April months are: 1898, 1910, 1913, 1919, 1958, 1979, 1984, 2005, 2010 and 2020.

For further information Google: climatediceandthebutterfly

https://www.sunlive.co.nz/blogs/14612-solar-activity-and-next-maunder-minimum.html

Solar Activity and the next Maunder Minimum

The ‘Maunder Minimum' is the name given to the period from 1645 to 1715 when the number of sunspots – ‘storms' on the sun – became almost zero.

The period is named after the solar astronomer Edward Walter Maunder (1851-1928), who was working at The Royal Observatory at Greenwich when he discovered the dearth of sunspots during this period.

During one 30-year period within the Maunder Minimum there were only about 50 sunspots compared with a more typical 40,000. Maunder was a driving force in the foundation of the British Astronomical Association and a Fellow of the Royal Astronomical Society.

The sun was well observed during the period of the Maunder Minimum and this lack of sunspots is well documented. This period of solar inactivity corresponded to a climatic period called the ‘Little Ice Age' when in Europe rivers that were normally ice-free, froze and snow fields remained at low altitudes throughout the year.

There is evidence the sun had similar periods of inactivity during the years 1100-1250 and 1460-1550. Sunspots generally follow a cycle of about 11 years, but cycles have varied from eight-15 years. The connection between solar activity and the earth's climate is an area of ongoing and sometimes controversial research.

An approaching Grand Solar Minimum is gaining “support” including NASA with their recent SC25 prediction — though they stay clear of the implications. NASA’s forecast for the next solar cycle (25) reveals it will be the weakest of the last 200 years.

The maximum of this next cycle — measured in terms of sunspot number, a standard measure of solar activity level — could be 30 to 50% lower than the most recent one. The agency’s results show that the next cycle will start in 2020 and reach its maximum in 2025:

The above chart and the following comment is from NASA’s official website (www.nasa.gov):

The new research was led by Irina Kitiashvili, a researcher with the Bay Area Environmental Research Institute at NASA’s Ames Research Center, in California’s Silicon Valley. It combined observations from two NASA space missions – the Solar and Heliospheric Observatory and the Solar Dynamics Observatory – with data collected since 1976 from the ground-based National Solar Observatory. One challenge for researchers working to predict the Sun’s activities is that scientists don’t yet completely understand the inner workings of our star. Plus, some factors that play out deep inside the Sun cannot be measured directly. They have to be estimated from measurements of related phenomena on the solar surface, like sunspots.

Time will tell whether the sun will once again go into another ‘Maunder Minimum' within the lifetime of the present generation, but if this happens we're likely to have a much colder climate for a few decades.

The sunspot number for most days during the last three months is zero. The number of days without sunspots during the last 365 days is 308.

A sunspot is a relatively dark, sharply defined region on the solar disc – marked by an umbra, dark area, which is 2000 degrees cooler than the effective photospheric temperature. The average diameter of a sunspot is 4000 km, but they can exceed 200,000 km.

Sunspots are temporary phenomena on the Sun's photosphere that appear as spots darker than the surrounding areas. They are regions of reduced surface temperature caused by concentrations of magnetic field flux that inhibit convection. Sunspots usually appear in pairs of opposite magnetic polarity. Individual sunspots or groups of sunspots may last anywhere from a few days to a few months, but eventually decay.

The NASA solar physics website, and other websites such as the Royal Observatory of Belgium, include information on sunspot numbers, the ‘Maunder Minimum' and sunspot cycle predictions.

The sunspot index is updated monthly and available from 1749. The last time the monthly sunspot number was above 100 during the last 14 years was in September 2002, when the value was 110. February 2014 had a sunspot value of 102.

The last time the value was above 200 was in August 1990, when the value was 200.3..

*************************************

For further information on a range of weather.climate matters Google climatediceandthebutterfly

https://www.sunlive.co.nz/blogs/14592-tropospheric-temperatures-january-1979-to-march-2020.html

Tropospheric Temperatures January 1979 to March 2020

The chart below shows that since 1979, when reliable satellite observations became available, there has been little overall trend in the average tropospheric temperatures, apart from milder/warmer temperatures since about 1997, and two significant warm periods associated with the El Nino events in 1998 and 2015-16

The latest global average temperatures of the troposphere updated to February 2020 - observed from US National Oceanic and Atmospheric Administration satellites – are computed by the University of Alabama at Huntsville in the United States. The data shows variations from the 30 year period 1981-2010.

Since 1979, NOAA satellites have been carrying instruments which measure the natural microwave thermal emissions from oxygen in the atmosphere. The intensity of the signals these microwave radiometers measure at different microwave frequencies is directly proportional to the temperature of different, deep layers of the atmosphere. Every month, researchers at the University of Alabama (Dr John Christy and Dr Roy Spencer) update global temperature datasets that represent the piecing together of the temperature data from a total of fourteen instruments flying on different satellites over the years.

The graph above represents the latest update; updates are usually made within the first week of every month. Contrary to some reports, the satellite measurements are not calibrated in any way with the global surface-based thermometer records of temperature. They instead use their own on-board precision redundant platinum resistance thermometers calibrated to a laboratory reference standard before launch.

The troposphere is the lowest layer of Earth's atmosphere.

It contains approximately 75 per cent of the atmosphere's mass and 99 per cent of its water vapour and aerosols.

The average depth of the troposphere is approximately 17 km in the middle latitudes.

The latest data for March 2020 is +0.48 degrees C.

The coolest months since 1979 were September 1984, with minus 0.49 degrees Celsius, and November 1984, with minus 0.42 degrees Celsius.

The warmest months were February 2016 with plus 0.83 degrees C, February and April 1998, and February 2020, all plus 0.76 degrees Celsius, and March 2016 plus 0.73 degrees, and April 2016 plus 0.73 degrees Celsius.

The chart shows the El Nino warming in the 1998 period, and 2015-16, and the Mount Pinatubo, volcanic cooling during 1992-1993.

For further information on a range of weather/climate matters Google Climatediceandthebutterfly

https://www.sunlive.co.nz/blogs/14564-tauranga-march-average-afternoon-temperatures-19132020.html

Tauranga March Average Afternoon Temperatures 1913-2020

Temperatures have been recorded in the Tauranga area at several sites during the last 100 years including the current Tauranga Airport site from June 1990.

The graph shows details of the average daily maximum temperatures, called simply ‘afternoon', for Tauranga for the months of March from 1913-2020.

March 1947 is not included because of incomplete data.

The average daily maximum temperature for March 2020 was 23.0 degrees Celsius.

The long-term average afternoon temperature in March for Tauranga is 22.5 degrees Celsius, ranging from the cool March months of 1960 with an average afternoon temperature of 20.4 degrees Celsius, and 1940 with an average afternoon temperature of 20.8 degrees Celsius, to the warm March months of 1916 (24.7 degrees Celsius), and 1938 and 1968 (24.6 degrees Celsius).

The graph of the average afternoon temperatures for March shows generally normal variations from March to March but with some warming over the last 20 years .

From 1913 to 2020, there have been twelve March months with an average afternoon temperature of 23.7 degrees Celsius or more, and 13 March months with an average afternoon temperature of 21.5 degrees Celsius or less.

The nine warmest March months – in terms of average afternoon temperatures on record –in chronological order are: 1913, 1914,1916, 1938, 1968, 2005, 2010, 2013, and 2019.

In contrast the 13 coolest March months – in terms of afternoon temperatures on record –in chronological order are: 1923, 1934,1936, 1940, 1944, 1945, 1949, 1960, 1974, 1976, 1992, 1993 and 1998.

The average afternoon temperature for March for the 48 years from 1914-1962 was 22.4 degrees Celsius, compared with an average of 22.6 degrees Celsius for the 48 years from 1963-2011.

For further information Google climatediceandthebutterfly

https://www.sunlive.co.nz/blogs/14544-tauranga-march-rainfalls-18982020.html

Tauranga March Rainfalls 1898-2020

Rainfalls for the month of March have been recorded in Tauranga since 1898 – except for 1904, 1908 and 1909.

This graph below shows the range of rainfalls from a high of 504 mm in 1979, to a low of 5 mm in 1943.

The second wettest March was in 1972, when 318 mm was recorded, and two March months – 1921 and 2010 – recorded 14 mm.

The long-term average rainfall for Tauranga for March is 109 mm. The rainfall for March 2020 was 41 mm.

The rainfall for the combined months of January+February+March was 71 mm. This is the second driest January+February+March period on record, the driest being 2013.

The graph shows no significant overall trend in rainfalls in March during the last 122 years, apart from a small increase in the average rainfall for the 50 years ending in 1960 of 103 mm, compared with 117 mm in the 50 years to 2010.

Since 1898, there have been eleven March months with a rainfall of 200 mm or more, and eleven March months with a rainfall of 30 mm or less.

The wettest March months in chronological order are: 1902,1918,1922,1935,1941,1944,1957,1962,1972,1979 and 1987.

The driest March months in chronological order are: 1903,1905,1921,1943,1951,1952,1953,1969, 2004, 2010 and 2013.

For further information Google: climatediceandthebutterfly

https://www.sunlive.co.nz/blogs/14512-global-temperatures-1996-february-2020.html

Global Temperatures 1996 – February 2020

Global temperatures are compiled for various areas including global (land-ocean), global (meteorological stations), three latitude bands,

and hemispheric, by the Goddard Institute for Space Studies of NASA.

The graph shows the monthly mean global surface temperature anomaly from the base period 1951-1980, for the period 1996- February 2020

For details see data.giss.nasa. (See graphs at the top right hand corner of the front web page and go to months)

The GISS Surface Temperature Analysis (GISTEMP) is an estimate of global surface temperature change. Graphs and tables are updated around the

middle of every month using current data files from NOAA GHCN v3 (meteorological stations), ERSST v4 (ocean areas), and SCAR (Antarctic stations),

combined as described in our December 2010 publication (Hansen et al. 2010). These updated files incorporate reports for the previous month and

also late reports and corrections for earlier month.

The basic GISS temperature analysis scheme was defined in the late 1970's when a method of estimating global temperature

change was needed for comparison with one-dimensional global climate models. The scheme was based on the finding that the correlation

of temperature change was reasonably strong for stations separated by up to 1200 km, especially at middle and high latitudes. This fact proved

sufficient to obtain useful estimates for global mean temperature changes.

The chart above shows that from 1997 to February 2020 there has been a small warming in the global monthly temperatures, and a relatively

warm period associated with the recent El Nino event.

For further information on a wide range of weather/climate matters.. Google: climatediceandtheweatherdice

https://www.sunlive.co.nz/blogs/14484-tropospheric-temperatures-1979-to-february-2020.html

Tropospheric Temperatures 1979 to February 2020

The chart below shows that since 1979, when reliable satellite observations became available, there has been little overall trend in the average tropospheric temperatures, apart from milder/warmer temperatures since about 1997, and two significant warm periods associated with the El Nino events in 1998 and 2015-16

The latest global average temperatures of the troposphere updated to February 2020 - observed from US National Oceanic and Atmospheric Administration satellites – are computed by the University of Alabama at Huntsville in the United States. The data shows variations from the 30 year period 1981-2010.

Since 1979, NOAA satellites have been carrying instruments which measure the natural microwave thermal emissions from oxygen in the atmosphere. The intensity of the signals these microwave radiometers measure at different microwave frequencies is directly proportional to the temperature of different, deep layers of the atmosphere. Every month, researchers at the University of Alabama (Dr John Christy and Dr Roy Spencer) update global temperature datasets that represent the piecing together of the temperature data from a total of fourteen instruments flying on different satellites over the years.

The graph above represents the latest update; updates are usually made within the first week of every month. Contrary to some reports, the satellite measurements are not calibrated in any way with the global surface-based thermometer records of temperature. They instead use their own on-board precision redundant platinum resistance thermometers calibrated to a laboratory reference standard before launch.

The troposphere is the lowest layer of Earth's atmosphere.

It contains approximately 75 per cent of the atmosphere's mass and 99 per cent of its water vapour and aerosols.

The average depth of the troposphere is approximately 17 km in the middle latitudes.

The latest data for February 2020 is +0.76 degrees C.

The coolest months since 1979 were September 1984, with minus 0.49 degrees Celsius, and November 1984, with minus 0.42 degrees Celsius.

The warmest months were February 2016 with plus 0.83 degrees C, February and April 1998, and February 2020, all plus 0.76 degrees Celsius, and March 2016 plus 0.73 degrees, and April 2016 plus 0.73 degrees Celsius.

The chart shows the El Nino warming in the 1998 period, and 2015-16, and the Mount Pinatubo, volcanic cooling during 1992-1993.

For further information on a range of weather/climate matters Google Climatediceandthebutterfly

https://www.sunlive.co.nz/blogs/14456-tauranga-february-average-afternoon-temperatures-19142020.html

Tauranga February Average Afternoon Temperatures 1914-2020

The average afternoon temperature for February 2020 was 26.5 degrees Celsius, which made February 2020 the warmest February since records began in 1913.

It's very common for areas such as Tauranga to have had different observation sites during the years; and the readings from the earlier sites have been adjusted to the present site using ‘standard climatological procedures'.

It's considered the temperature series described here is a fair and true record of what the temperature would have been if the current observation site (Tauranga Airport) had been used throughout the period.

It's important to note that in considering ‘climate change', the methodology used in computing an 'official' set of climate observations is very important – as otherwise erroneous conclusions may be drawn.

Traditionally, temperature observations have been recorded with a set of maximum and minimum temperature thermometers. These record the daily maximum temperature (usually recorded in mid-afternoon), and daily minimum temperature (usually recorded just before dawn).

This analysis of February temperatures for Tauranga is for the average daily maximum temperatures.

Rainfalls for the month of February have been recorded in Tauranga since 1898 (except for 1904, 1908, and 1909).

The graph of February rainfalls in Tauranga shows the range of rainfalls from a high of 343 mm in 1936 to a low of only 7 mm in 1973.

The graph shows predominantly "normal" variations from year to year.

Ten February months have had a rainfall of less than 15 mm. Nine February months also have had a rainfall of 200 mm or more.

The wettest February was 1936 with 343 mm, and the second wettest February was 2001 when 268 mm was recorded.

The driest February month was 1973 with 7 mm, and the February months of 1942, 1987, and 2011 each had a rainfall of 8 mm.

The rainfall for February 2020 was 10 mm. The long-term February rainfall for Tauranga is 90 mm.

In chronological order, the wettest nine February months were 1920, 1933, 1934, 1936, 1938, 1960, 1966, 2001, and 2004.

In chronological order, the driest nine February months were 1942, 1970, 1972, 1973, 1987, 1999, 2000, 2010, 2011 and 2020.

The combined rainfall in Tauranga for January and February of 30 mm was the driest since records began in 1898. Other dry January February months were 32mm in 1970, 34 mm in 1942, 1973,and 2019, plus 35 mm in 2013.

For further information on a range of weather/climate matters Google climatediceandthebutterfly

https://www.sunlive.co.nz/blogs/14404-tropospheric-temperatures-1979-to-january-2020.html

Tropospheric Temperatures 1979 to January 2020

The chart below shows that since 1979, when reliable satellite observations became available, there has been little overall trend in the average tropospheric temperatures, apart from milder/warmer temperatures since about 1997, and two significant warm periods associated with the El Nino events in 1998 and 2015-16.

The latest global average temperatures of the troposphere updated to January 2020 - observed from US National Oceanic and Atmospheric Administration satellites – are computed by the University of Alabama at Huntsville in the United States. The data shows variations from the 30 year period 1981-2010.

Since 1979, NOAA satellites have been carrying instruments which measure the natural microwave thermal emissions from oxygen in the atmosphere. The intensity of the signals these microwave radiometers measure at different microwave frequencies is directly proportional to the temperature of different, deep layers of the atmosphere. Every month, researchers at the University of Alabama (Dr John Christy and Dr Roy Spencer) update global temperature datasets that represent the piecing together of the temperature data from a total of fourteen instruments flying on different satellites over the years.

The graph above represents the latest update; updates are usually made within the first week of every month. Contrary to some reports, the satellite measurements are not calibrated in any way with the global surface-based thermometer records of temperature. They instead use their own on-board precision redundant platinum resistance thermometers calibrated to a laboratory reference standard before launch.

The troposphere is the lowest layer of Earth's atmosphere.

It contains approximately 75 per cent of the atmosphere's mass and 99 per cent of its water vapour and aerosols.

The average depth of the troposphere is approximately 17 km in the middle latitudes.

The latest data for January 2020 is +0.56 degrees C.

The coolest months since 1979 were September 1984, with minus 0.49 degrees Celsius, and November 1984, with minus 0.42 degrees Celsius.

The warmest months were February 2016 with plus 0.83 degrees C, February and April 1998, both plus 0.76 degrees Celsius, and March 2016 plus 0.73 degrees, and April 2016 plus 0.73 degrees Celsius.

The chart shows the El Nino warming in the 1998 period, and 2015-16, and the Mount Pinatubo, volcanic cooling during 1992-1993.

For further information Google: climatediceandthebutterfly

https://www.sunlive.co.nz/blogs/14376-tauranga-annual-rainfalls-18982019.html

Tauranga Annual Rainfalls 1898-2019

Monthly rainfalls for Tauranga have been recorded at several recording sites during the last 122 years.

From January 1898 to December 1904, the observation site was described as the Tauranga Harbour, from November 1904 to April 1907 the site was described as simply ‘Tauranga'.

From January 1910 to December 1923 the site was Waikareao, in Otumoetai; from January 1924 to September 1940 the site was at 148 Waihi Rd, in Judea; from October 1940 to January 1941 the site was at Te Puna; and from February 1941 to now, the site is Tauranga Airport.

The methodology use in adjusting the older sites to the current observing site is published in the ‘NZ Meteorological Service Miscellaneous Publication' No 180 in 1984.

It is considered that the homogeneous rainfall series described here is a fair and true record of what the rainfall would have been if the current observation site (Tauranga Airport) had been used since 1898.

This should be coupled with the understanding that although standard accepted methodologies have been used, any adjustments are only estimates of what would have occurred if the location of the rainfall records had always been in the same place with the same surroundings and the same or similar recording gauge.

In terms of climate change (such as is it getting wetter or drier, or warmer or colder), the methodology used in computing an ‘official' set of climate observations is very important, as otherwise erroneous conclusions may be drawn.

The long-term average rainfall for Tauranga for the calendar year is 1300 mm, ranging from a low of 747 mm in 2002, to a high of 2049 mm in 1962.

For comparison, the rainfall for the last year, 2019, was 787 mm which was the third lowest since record began in 1898.

Since 1898, there have been only six years with a rainfall of less than 900 mm, they are 1914, 1982, 1993, 2002, 2015 and 2019.

And there has been only four years with a rainfall of more than 1800 mm; they are the two consecutive years of 1916 and 1917, plus 1938 and 1962.

The ten wettest years on record are: 1962 which had 2049 mm or 57 per cent above of the long-term average, while 1917 had 1985 mm or 52 per cent above average. Also, 1916 had 1941 mm or 49 per cent above average, plus 1938 (1817 mm), 1920 (1789 mm), 1956 (1777 mm), 1979 (1730 mm), 2011 (1696 mm), 2005 (1682 mm), and 1935 (1670 mm).

In chronological order, these wettest years occurred in 1916, 1917, 1920, 1935, 1938, 1956, 1962, 1979, 2005 and 2011.

In contrast, the 12 driest years on record are: 2002 (747 mm or 48 per cent below the long-term average), 1914 (773 mm or 41 per cent below the long-term average), 2019 (787 mm or 43 per cent of the long-term average), 2015 (842 mm or 36 per cent below the long-term average), 1982 (842 mm or 36 per cent below the long-term average), plus 1993 (863 mm), 1906 (950 mm), 1919 (962 mm), 1997 (978 mm), 1973 (989 mm), 1986 (991 mm), and 1999 (1002 mm).

In chronological order, these driest years occurred in 1906, 1914, 1919, 1973, 1982, 1986, 1993, 1997, 1999, 2002, 2015, and 2019.

The average rainfall in Tauranga for the 50 years 1911-60 was 1365 mm, compared with the average rainfall for the 50 years 1961-2010 of 1263 mm.

For further information on a range of weather/climate matters Google climatediceandthebutterfly

https://www.sunlive.co.nz/blogs/14352-tauranga-january-average-afternoon-temperatures-19142020.html

Tauranga January Average Afternoon Temperatures 1914-2020

Temperatures have been recorded in the Tauranga area at several sites during the last 100 years, including the current Tauranga Airport site from June 1990.

The graph above shows details of the average daily maximum temperatures (called simply ‘afternoon') for Tauranga for January from 1914-2020.

The long-term average afternoon temperature in January for Tauranga is 23.8 degrees Celsius, ranging from the cool January months of 1920, with 21.6 degrees Celsius, and 1939 with 21.8 degrees Celsius, to the very warm January month of 1935, with 27.7 degrees Celsius, and January 2019 with 26.7 degrees Celsius.

The average afternoon temperature in January 2020 was 25.4 degrees Celsius, the ninth warmest January on record.

The average January afternoon temperature during the 50 years from 1963 to 2011 of 23.8 degrees Celsius, is the same average recorded in the 50 year period from 1914 to 1962.

From 1914 to 2020, there have been ten January months with an average afternoon temperature of 25.3 degrees Celsius or higher, and seven January months with an average afternoon temperature of 22.5 degrees Celsius or lower.

The ten-warmest January months (in terms of afternoon temperatures), on record, in chronological order, are 1914, 1915, 1935, 1970, 1957, 1999, 2009, 2015, 2018, and 2019. By contrast. the seven coolest January months on record, in chronological order, are 1918, 1920, 1922, 1925, 1930, 1939, and 1980.

For further information on a range of weather/climate matters.. Google Climateeyeandthebutterfy.

https://www.sunlive.co.nz/blogs/14328-tauranga-annual-average-afternoon-temperatures-19142019.html

Tauranga Annual Average Afternoon Temperatures 1914-2019

Temperatures have been recorded in the Tauranga area at several sites in the last 100 years, including the current Tauranga Airport site from June 1990.

It's very common for areas such as Tauranga to have had different observation sites during the years, and readings from the earlier sites have been adjusted to the present site using standard climatologically procedures.

The temperature series described here is a record of what the temperature would have been if the current observation site, Tauranga Airport, had been used throughout the period.

It's important to note, in considering climate change, the methodology used in computing an official set of climate observations is very important as otherwise erroneous conclusions may be drawn. Traditionally, temperature observations have been recorded with a set of maximum and minimum temperature thermometers.These record the daily maximum temperature, usually recorded in mid-afternoon, and daily minimum temperature, usually recorded just before dawn.

This analysis of temperatures for Tauranga is for average daily maximum temperatures.

The graph below shows details of the average annual daily maximum temperatures (called simply 'afternoon'), for Tauranga for the years 1914-2019.

The long-term average afternoon temperatures for Tauranga for a calendar year is 18.6 degrees Celsius, including the cool years of 18.1 degrees Celsius in 1976, 18.1 degrees Celsius in 1992, 18.2 degrees Celsius in 1923, and 18.3 degrees Celsius in 1918.

In contrast, Tauranga's warmest years (in terms of the average afternoon temperature) are: 20.4 degrees in 2019, 20.2 degrees Celsius in 2013, 20.1 degrees Celsius in 1916, 20.0 degrees Celsius in 1998, 19.9 degrees Celsius in 2010, 2016 and 2018, and 19.8 degrees Celsius in 1915, 2011, 2014, and 2017.

The average afternoon temperature in 2019 was 20.4 degrees Celsius, which made 2019 the warmest year on record.

Since 1914, there have been fifteen calendar years with an average afternoon temperature of 19.5 degrees Celsius or more. In chronological order these years are: 1914, 1915, 1916, 1928, 1998, 1999, 2005, 2010, 2011, 2013, 2014, 2015, 2016, 2017, 2018 and 2019.

In contrast, there have been 11 calendar years with an average afternoon temperature of 18.5 degrees Celsius or less. In chronological order these years are: 1918, 1920, 1923, 1941, 1945, 1965, 1976, 1977, 1980, 1991, and 1992.

The graph of the average afternoon temperatures for the years 1914-2018 shows generally normal variations from year to year from 1915 to the mid-1990's, followed by several years of above-average temperatures, including the last recent seven out of the last eight years.

The annual average afternoon temperature shows a warming of about 0.8 degrees Celsius during the 51 years from 1963-2013 from 19.0 degrees Celsius, compared with 18.2 degrees Celsius during the 49 years from 1914-1962.

https://www.sunlive.co.nz/blogs/14304-tauranga-december-rainfalls-18982019.html

Tauranga December Rainfalls 1898-2019

The graph below shows the range of Tauranga's December rainfalls, from an extreme high of 447 mm in 1962 to a low of only 4 mm in 1930.

The second wettest December was 2018, when 278 mm was recorded

The second driest December was in 1994, when only 14 mm fell.

The rainfall for December 2019 was 57 mm.

The long-term average rainfall for Tauranga for December is 100 mm.

The graph of the December rainfall shows, at first glance, normal variations from year to year.

However, there has been an increase in December rainfalls during the last few decades. Indeed, the average December rainfall in Tauranga for the 50-year period from 1961-2010 of 109 mm, is 20 per cent higher than the rainfall for the 50-year period 1911-1960. In contrast, three recent December months (2015, 2016, 2017) have had low rainfalls of 18 mm, 44 mm, and 29 mm.

Since 1898, there have been nine Decembers with a rainfall of 200 mm or more, six of which occurred during the period 1962 to 2018. Seven December months have experienced rainfalls of 30 mm or less. Of significance are the high rainfalls in the consecutive December months of 1962 and 1963, of 447 mm and 224 mm respectively.

In chronological order, the nine-wettest Decembers are 1924 with 225 mm, 1928 with 227 mm, 1936 with 240 mm, 1962 with 447 mm, 1963 with 224 mm, 1996 with 241 mm, 2001 with 208 mm, 2011 with 276 mm, and 2018 with 278 mm.

In contrast, the eighth-driest December months in chronological order are 1902 with 27 mm, 1912 with 22 mm, 1919 with 22 mm, 1930 with 4 mm, 1986 with 30 mm, 1990 with 21 mm, 1994 with 14 mm, and 2015 with 18 mm.

For further information on a range of weather/climate matters Google: climatediceandthebutterfly

https://www.sunlive.co.nz/blogs/14276-tauranga-average-afternoon-temperatures-december-19132019.html

Tauranga Average Afternoon Temperatures for December 1913-2019

Temperatures have been recorded in the Tauranga area at several sites during the last 100 years, including the current Tauranga Airport site from June 1990.

The average afternoon temperature in December 2019 was 24.1 degrees Celsius, the third warmest December since records commenced in 1913.

The graph below shows details of the average daily maximum temperatures, called simply ‘afternoon', for Tauranga for December from 1913-2019.

The long-term average afternoon temperature in December for Tauranga is 22.1 degrees Celsius, ranging from the ‘cool' December months of 2004 (20.1), 1968 (20.5) and 1944 and 1951 (both 20.7), to the ‘warm' December months of 1940 (24.4), 2017 (24.3), 1937 (24.0), and 1990 (23.8 degrees C).

The graph of the average afternoon temperatures for December shows generally normal variations from December-to-December during the last 100 years.

The average December afternoon temperature during the 50 years from 1963 to 2011 of 22.2 degrees Celsius which is the same as that recorded in the 50 years from 1914 to 1961.

The average afternoon temperature of 23.0 degrees Celsius or more has been recorded 21 times since 1913, and 12 December months have had an an average afternoon temperature of 21.0 degrees Celsius or less.

The nine warmest December months (in terms of afternoon temperatures), on record, in chronological order, are 1930, 1934, 1937, 1940, 1990, 1993, 1994, 2017 and 2019.

By contrast, the seven coolest December months (in terms of afternoon temperatures), on record, in chronological order, are 1921, 1946, 1951, 1962, 1968, 1977, and 2004.

For further information on a range of weather/climate matters Google: climatediceandthebutterfly

https://www.sunlive.co.nz/blogs/14248-solar-activity-and-spotless-days.html

Solar Activity and Spotless Days

The NASA solar physics website, and other websites such as the Royal Observatory of Belgium, include information on sunspot numbers, spotless days, the ‘Maunder Minimum' and sunspot cycle predictions.

A sunspot is a relatively dark, sharply defined region on the solar disc – marked by an umbra, dark area, which is 2000 degrees cooler than the effective photospheric temperature. The average diameter of a sunspot is 4000 km, but they can exceed 200,000km.

The sunspot index is updated monthly and is available from 1749. The last time the value was much above 200 was in August 1990.

Solar observers have noticed that since mid-2016, the Sun has occasionally been devoid of sunspots. These spotless disks will gradually become a familiar feature as the solar cycle is heading for its next minimum, currently expected by 2020 and probably has already started. The number of spotless days can vary significantly from one solar cycle transit to another. For example, during the previous minimum solar cycle 24 (around 2008), 817 spotless days were recorded, whereas the minimum period leading into solar cycle 23 (around 1996) counted only 309 such blemishless days.

The current solar cycle 24 will gradually give way to the new solar cycle 25, and several consecutive days and even periods of 30 or more consecutive days without sunspots will become the norm. The Belgium SILSO website has created a “Spotless Days page”. This page contains graphs and tables on the accumulated number of spotless days, stretches of spotless days, and comparisons to other solar cycles.

The previous minimum (solar cycle 24) surprised many solar scientists and solar observers by being the deepest in nearly 90 years. Will the upcoming solar cycle minimum show as many spotless days, or will solar cycle 25 take off much faster than expected? The “Spotless Days page” provides a front-row seat on the current status of the solar cycle minimum and the number of spotless days. Enjoy!

Since 1849, there have been 114 years (including 2019) with at least one spotless day. The chart below shows the 25 years with the highest number of spotless days. 1913 had 311 spotless days, 1901 had 287 spotless days, 1878 had 280 spotless days, while last year 2019 which ranks fourth since 1849 had 273 spotless days.

The ‘Maunder Minimum' is the name given to the period from 1645 to 1715 when the number of sunspots – ‘storms' on the sun – became almost zero. The period is named after the solar astronomer Edward Walter Maunder (1851-1928), who was working at The Royal Observatory at Greenwich when he discovered the dearth of sunspots during this period.

During one 30-year period within the Maunder Minimum there were only about 50 sunspots compared with a more typical 40,000. Maunder was a driving force in the foundation of the British Astronomical Association and a Fellow of the Royal Astronomical Society.The sun was well observed during the period of the Maunder Minimum and this lack of sunspots is well documented. This period of solar inactivity corresponded to a climatic period called the ‘Little Ice Age' when in Europe rivers that were normally ice-free, froze and snow fields remained at low altitudes throughout the year. There is evidence the sun had similar periods of inactivity during the years 1100-1250 and 1460-1550. Sunspots generally follow a cycle of about 11 years, but cycles have varied from eight-15 years.

The connection between solar activity and the earth's climate is an area of ongoing and sometimes controversial research.Time will tell whether the sun will once again go into another ‘Maunder Minimum' within the lifetime of the present generation with very many spotless days , but if this happens we're likely to have a much colder climate for a few decades.

The sunspot number for many days during the last 3 months is zero.

For further information on a range of weather and climate matters see: Google climatediceandthebutterfly

https://www.sunlive.co.nz/blogs/14096-global-temperatures-1996-october-2019.html

Global Temperatures 1996 – October 2019

Global temperatures are compiled for various areas including global (land-ocean), global (meteorological stations), three latitude bands,

and hemispheric, by the Goddard Institute for Space Studies of NASA.

The graph shows the monthly mean global surface temperature anomaly from the base period 1951-1980, for the period 1996- October 2019.

For details see data.giss.nasa. (See graphs at the top right hand corner of the front web page and go to months)

The GISS Surface Temperature Analysis (GISTEMP) is an estimate of global surface temperature change. Graphs and tables are updated around the

middle of every month using current data files from NOAA GHCN v3 (meteorological stations), ERSST v4 (ocean areas), and SCAR (Antarctic stations),

combined as described in our December 2010 publication (Hansen et al. 2010). These updated files incorporate reports for the previous month and

also late reports and corrections for earlier month.

The basic GISS temperature analysis scheme was defined in the late 1970's when a method of estimating global temperature

change was needed for comparison with one-dimensional global climate models. The scheme was based on the finding that the correlation

of temperature change was reasonably strong for stations separated by up to 1200 km, especially at middle and high latitudes. This fact proved

sufficient to obtain useful estimates for global mean temperature changes.

The chart above shows that from 1997 to October 2019 there has been a small warming in the global monthly temperatures, and a relatively

warm period associated with the recent El Nino event.

For further information on a wide range of climate matters see https://sites.google.com/images/climatediceandthebutterfly/

*******

The physicist Leo Szilard once announced to his friend Hans Bethe that he was thinking of keeping a diary: 'I don't intend to publish, I am merely going to record the facts for the information of God.' 'Don't you think God knows the facts?' Bethe asked. 'Yes' said Szilard. "He knows the facts, but he does not know THIS version of the facts' "(From Hans Christian von Baeyer, "Taming the Atom" (from the preface paragraph in "A Short History of Nearly Everything", by Bill Bryson, A Black Swan Book, 2004)

https://www.sunlive.co.nz/blogs/14068-the-southern-oscillation-index.html

The Southern Oscillation Index

The Southern Oscillation Index (SOI) is a standardized index based on the observed sea level pressure differences between Tahiti and Darwin, Australia.

The SOI is a leading measure of the large-scale fluctuations in air pressure occurring between the western and eastern tropical Pacific (i.e., the state of the Southern Oscillation) during El Niño and La Niña episodes.

In general, smoothed time series of the SOI correspond very well with changes in ocean temperatures across the eastern tropical Pacific. The negative phase of the SOI represents below-normal air pressure at Tahiti and above-normal air pressure at Darwin. The positive phase of the SOI represents above-normal air pressure at Tahiti and below-normal air pressure at Darwin.

Prolonged periods of negative SOI values coincide with abnormally warm ocean waters across the eastern tropical Pacific typical of El Niño episodes. In contrast, prolonged periods of positive SOI values coincide with abnormally cold ocean waters across the eastern tropical Pacific typical of La Niña episodes. Sustained negative values of the SOI below −8 often indicate El Niño episodes.These negative values are usually accompanied by sustained warming of the central and eastern tropical Pacific Ocean, a decrease in the strength of the Pacific Trade Winds.

Sustained positive values of the SOI above +8 are typical of a La Niña episode.They are associated with stronger Pacific trade winds and warmer sea temperatures to the north of Australia. Waters in the central and eastern tropical Pacific Ocean become cooler during this time.

The graph below ( from the Australian Bureau of Meteorology, BOM) shows monthly values of the SOI from 1880 to November 2019.

The 30-day Southern Oscillation Index (SOI) for the 30 days ending 10 November was −5.7. The 90-day value was −9.1. The 30-day SOI values have remained fairly similar and within the ENSO-neutral range for about three and a half weeks.

Sustained negative values of the SOI below −7 typically indicate El Niño while sustained positive values above +7 typically indicate La Niña. Values between +7 and −7 generally indicate neutral conditions.

El Nino and La Nina weather affects over New Zealand (Source Niwa)

During El Niño, New Zealand tends to experience stronger or more frequent winds from the west in summer, typically leading to drought in east coast areas and more rain in the west.

In winter, the winds tend to be more from the south, bringing colder conditions to both the land and the surrounding ocean.

In spring and autumn south–westerly winds are more common.

La Niña events have different impacts on New Zealand's climate. More north–easterly winds are characteristic, which tend to bring moist, rainy conditions to the north–east of the North Island, and reduced rainfall to the south and south–west of the South Island.

Therefore, some areas, such as central Otago and South Canterbury, can experience drought in both El Niño and La Niña.

Warmer than normal temperatures typically occur over much of the country during La Niña, although there are regional and seasonal exceptions.

Although ENSO events have an important influence on New Zealand's climate, it accounts for less than 25 per cent of the year to year variance in seasonal rainfall and temperature at most New Zealand measurement sites.

For further information see: https://sites.google.com/images/climatediceandthebutterfly/

***********************

The physicist Leo Szilard once announced to his friend Hans Bethe that he was thinking of keeping a diary: 'I don't intend to publish, I am merely going to record the facts for the information of God.' 'Don't you think God knows the facts?' Bethe asked. 'Yes' said Szilard. ‘He knows the facts, but he does not know THIS version of the facts'

"(From Hans Christian von Baeyer, "Taming the Atom" (from the preface paragraph in "A Short History of Nearly Everything", by Bill Bryson, A Black Swan Book,

https://www.sunlive.co.nz/blogs/14040-tauranga-october-rainfalls-18982019.html

Tauranga October Rainfalls 1898-2019

The graph below shows the range of Tauranga's October rainfalls, from an extreme high of 357 mm in 1916 to a low of only 7 mm in 1984.

The second wettest October was 1928, when 269 mm was recorded; and the second driest October was in 1928, when only 11 mm fell.

The long-term average rainfall for Tauranga in the month of October is 110 mm.

The rainfall in October 2019 was 91 mm.

The graph of the October rainfall shows generally normal variations from year to year.

Since 1898, there have been 11 October months with a rainfall of 200 mm or more (10 of which occurred during the period 1900-1958), and only one October month since then has recorded this much. Ten October months have also experienced rainfalls of 25 mm or less.

In chronological order the eleven wettest October months are 1900, 1905, 1916, 1918, 1921, 1926, 1928, 1941, 1952, 1958, and 1983. In contrast the eleventh driest October months are 1906, 1938, 1963, 1965, 1969, 1973, 1984, 1993, 2010, 2013, and 2015.

For further information see: https://sites.google.com/images/climatediceandthebutterfly/

https://www.sunlive.co.nz/blogs/14004-tauranga-october-average-afternoon-temperatures-19132019.html

details of the average daily maximum temperatures (called simply ‘afternoon') for Tauranga for October from 1913-2019.

The average afternoon temperature for October 2019 for Tauranga was 18.5 degrees C, which was just 0.4 degrees milder than the average over the last 95 years.

The long-term average afternoon temperature in October for Tauranga is 18.1 degrees Celsius, ranging from the cool October months of 1964 (15.7 degrees Celsius), and 1992 (16.5 degrees Celsius), to the warm October months of 2013 (20.3 degrees Celsius), and 1915 (19.9 degrees Celsius).

The graph of the average afternoon temperatures for October shows generally normal variations from October to October during the last 100 years.

The average October afternoon temperatures during the 50 years from 1963-2011 of 18.0 degrees Celsius is slightly cooler than the 18.3 degrees Celsius recorded in the 50 years from 1914-1961.

From 1913 to 2018, there have been fifteen October months with an average afternoon temperature of 19.0 degrees Celsius or more; and eight October months have had an average afternoon temperature of 17.0 degrees Celsius or less.

The five warmest October months (in terms of afternoon temperatures), on record, in chronological order, are 1913, 1915, 1940, 2013, and 2015.

By contrast, the fifth coolest October months (in terms of afternoon temperatures), on record, in chronological order, are 1941, 1964, 1978, 1982, and 1992.

For further information see: https://sites.google.com/images/climatediceandthebutterfly/

The physicist Leo Szilard once announced to his friend Hans Bethe that he was thinking of keeping a diary: 'I don't intend to publish, I am merely going to record the facts for the information of God.' 'Don't you think God knows the facts?' Bethe asked. 'Yes' said Szilard. ‘He knows the facts, but he does not know THIS version of the facts'

"(From Hans Christian von Baeyer, "Taming the Atom" (from the preface paragraph in "A Short History of Nearly Everything", by Bill Bryson, A Black Swan Book, 2004)

https://www.sunlive.co.nz/blogs/13972-tropospheric-temperatures-1979-to-september-2019.html

Tropospheric Temperatures 1979 to September 2019

The chart below shows that since 1979, when reliable satellite observations became available, there has been little overall trend in the average tropospheric temperatures, apart from milder/warmer temperatures since about 1997, and two significant warm periods associated with the El Nino events in 1998 and 2015-16.

The latest global average temperatures of the troposphere updated to October 2019 - observed from US National Oceanic and Atmospheric Administration satellites – are computed by the University of Alabama at Huntsville in the United States. The data shows variations from the 30 year period 1981-2010.

Since 1979, NOAA satellites have been carrying instruments which measure the natural microwave thermal emissions from oxygen in the atmosphere. The intensity of the signals these microwave radiometers measure at different microwave frequencies is directly proportional to the temperature of different, deep layers of the atmosphere. Every month, researchers at the University of Alabama (Dr John Christy and Dr Roy Spencer) update global temperature datasets that represent the piecing together of the temperature data from a total of fourteen instruments flying on different satellites over the years.

The graph above represents the latest update; updates are usually made within the first week of every month. Contrary to some reports, the satellite measurements are not calibrated in any way with the global surface-based thermometer records of temperature. They instead use their own on-board precision redundant platinum resistance thermometers calibrated to a laboratory reference standard before launch.

The troposphere is the lowest layer of Earth's atmosphere.

It contains approximately 75 per cent of the atmosphere's mass and 99 per cent of its water vapour and aerosols.

The average depth of the troposphere is approximately 17 km in the middle latitudes.

The latest data for September 2019 is +0.61 degrees C.

The coolest months since 1979 were September 1984, with minus 0.49 degrees Celsius, and November 1984, with minus 0.42 degrees Celsius.

The warmest months were February 2016 with plus 0.83 degrees C, February and April 1998, both plus 0.76 degrees Celsius, and March 2016 plus 0.73 degrees, and April 2016 plus 0.73 degrees Celsius.

The chart shows the El Nino warming in the 1998 period, and 2015-16, and the Mount Pinatubo, volcanic cooling during 1992-1993.

****************************

The physicist Leo Szilard once announced to his friend Hans Bethe that he was thinking of keeping a diary: 'I don't intend to publish, I am merely going to record the facts for the information of God.' 'Don't you think God knows the facts?' Bethe asked. 'Yes' said Szilard. ‘He knows the facts, but he does not know THIS version of the facts'

"(From Hans Christian von Baeyer, "Taming the Atom" (from the preface paragraph in "A Short History of Nearly Everything", by Bill Bryson, A Black Swan Book, 2004)

https://www.sunlive.co.nz/blogs/13936-do-solar-magnetic-variations-affect-climate.html

Do Solar Magnetic Variations affect the Climate?

The changes in the SOI at the time of each IMF change of direction (sector boundary crossing) were found to be very large on the average during the two extreme El Nino years 1997 and 2015 (accompanied by very low negative values of the SOI), and also during the extreme La Nina years 2010 and 2011 (accompanied by very high positive values of the SOI). Values of the SOI were generally less (positive or negative) in the remaining years of the study and the apparent effect on the SOI at the time of each sector boundary crossing in those years generally smaller, but still noteworthy.

The revelation of these results leaves us with one big question:

“As it seems most unlikely that the results are due to pure chance, what exactly is the mechanism causing them?”

Are interplanetary/solar magnetic (tidal) forces responsible? Could these influences be largely or at least partly the cause of the global climate changes that we are now witnessing?

A paper by Italian scientists SA Capuano et al published in 2018 offers a further insight into this subject. The extract from the published paper includes the following:

The debated question on the possible relation between the Earth’s magnetic field and climate has been usually focused on direct correlations between different time series representing both systems.

However, the physical mechanism able to potentially explain this connection is still an open issue. Finding hints about how this connection could work would suppose an important advance in the search of an adequate physical mechanism.

Here, we propose an innovative information-theoretic tool, i.e. the transfer entropy (which is the transfer of information between two random processes) as a good candidate for this scope because is able to determine, not simply the possible existence of a connection, but even the direction in which the link is produced.

We have applied this new methodology to two real time series, the South Atlantic Anomaly (SAA) area extent at the Earth’s surface (representing the geomagnetic field system) and the Global Sea Level (GSL) rise (for the climate system) for the last 300 years, to measure the possible information flow and sense between them.

This connection was previously suggested considering only the long-term trend while now we study this possibility also in shorter scales. The new results seem to support this hypothesis, with more information transferred from the SAA to the GSL time series, with about 90% of confidence level.

This result provides new clues on the existence of a link between the geomagnetic field and the Earth’s climate in the past and on the physical mechanism involved because, thanks to the application of the transfer entropy, we have determined that the sense of the connection seems to go from the system that produces geomagnetic field to the climate system.

Of course, the connection does not mean that the geomagnetic field is fully responsible for the climate changes, rather that it is an important driving component to the variations of the climate.

Sunspots Update

As of October 21, there have been 213 days in 2019 when the sun has had no sunspots. Data on spotless days are available from 1849 and the year 1913 with 311 spotless days is the highest spotless calendar year. The year 2019 with 213 spotless days is currently the 11th most spotless days year ( since 1849) .

For further information on a range of weather and climate and climate matters see: https://sites.google.com/images/climatediceandthebutterfly/

The physicist Leo Szilard once announced to his friend Hans Bethe that he was thinking of keeping a diary: 'I don't intend to publish, I am merely going to record the facts for the information of God.' 'Don't you think God knows the facts?' Bethe asked. 'Yes' said Szilard. "He knows the facts, but he does not know THIS version of the facts'

"(From Hans Christian von Baeyer, "Taming the Atom" (from the preface paragraph in "A Short History of Nearly Everything", by Bill Bryson, A Black Swan Book, 2004)

https://www.sunlive.co.nz/blogs/13900-tauranga-september-average-afternoon-temperatures-19132019.html

Tauranga September Average Afternoon Temperatures 1913-2019

Temperatures have been recorded in the Tauranga area at several sites in the last 100 years, including the current Tauranga Airport site from June 1990.

The graph shows details of the average daily maximum temperatures (simply called “afternoon”) for Tauranga for September from 1913-2019.

The long-term average afternoon temperature in September for Tauranga is 16.6 degrees C, ranging from the “cool” September months of 1964 (14.8 degrees C), and 1977 (14.9 degrees C), to the “warm” September months of 1915 (18.4 degrees C), and 18.3 degrees in 1914.

The afternoon temperature for 2019 was 16.8 degrees C, which was the one of the coolest Septembers in the last decade.

The graph of the average afternoon temperatures for September shows generally "normal" variations from September to September during the last 100 years, but five of the warmest six September months occurred from 1913 to 1921.

From 1913 to 2019, there have been ten September months with an average afternoon temperature of 17.5 degrees C or more, and eight September months with an average afternoon temperature of less than 15.4 degrees C.

The tenth “warmest” September months (in terms of afternoon temperatures) on record, in chronological order, are 1913, 1914, 1915, 1916, 1921, 1926, 1940, 2006, 2009 and 2014.

By contrast, the eighth “coolest” September months (in terms of afternoon temperatures) on record, in chronological order, are 1935, 1964, 1967, 1977, 1992, 1993, 1994 and 1997.

The average afternoon temperature during September for the period 1914-62 was 16.6 degrees, compared with 16.5 degrees from 1963-2011.

For further information see: https://sites.google.com/images/climatediceandthebutterfly/

********************************************

https://www.sunlive.co.nz/blogs/13876-tauranga-september-rainfalls.html

Tauranga September Rainfalls

Rainfalls for the month of September have been recorded in Tauranga since 1898, except for 1904, 1907, 1908, and 1909.

The graph below shows the range of rainfalls from an extreme high of 274 mm in 1973 to a low of only 16 mm in 1965.

The second wettest September was in 1900, when 256 mm was recorded, and the second driest September was in 1944, when only 27 mm fell. The long-term average rainfall for Tauranga for September is 105 mm.

The graph of the September rainfall shows normal variations from year to year. Since 1898, there have been five Septembers with a rainfall of 200 mm or more (four of which occurred during the period 1900 to 1928, but there's only been one since then), compared with seven September months with a rainfalls of 40 mm or less.

The rainfall for September 2019 was 97 mm.

In chronological order, the ten wettest September months (rainfalls over 180 mm) are 1900,1912,1919,1923,1928,1946,1960,1969,1971,1973, and 2017.

In contrast the twelfth driest September months (rainfalls of 50 mm or less) are 1910, 1913, 1914, 1921, 1922, 1944, 1965, 1993, 1987, 2006, 2011 and 2018.

The average rainfall for Tauranga for September for the 50 years 1961-2010 of 103 mm is similar to the rainfall for the previous 50 years (1910-1960).

For further information on a range of weather/climate matters see https://sites.google.com/images/climatediceandthebutterfly/

******

https://www.sunlive.co.nz/blogs/13836-climate-change-2019-and-villach-1985-what-is-connection.html

Climate Change 2019 and Villach 1985: What is the connection?

Among the many climate science meetings I have attended, the most significant, at least in term of climate change is concerned, was my involvement in the UN sponsored International Conference held in the beautiful town Villach, in Austria in October 1985.

One hundred experts from 30 countries attended the meeting (in contrast to ten to twenty thousand who now attend such meetings), and I was privileged to be the only New Zealander invited.

We were all there as experts - and not representing our respective organisations - in various fields of science, endeavouring to do the best we could in looking at the complexities of climate science.

This conference predated by three years the establishment of the Intergovernmental Panel on Climate Change (IPCC) established by the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP).

The first session of the IPCC was held in Geneva in November 1988 and again I was the only person from New Zealand invited to participate.

Among the principal findings of this conference was that "while other factors, such as aerosol concentration, changes in solar energy input, and changes in vegetation, may also influence climate, the greenhouse gases are likely to be the most important cause of climate change over the next century”.

At that time, even though I was partly responsible for the writing of the above paragraph, I along with a few of my colleagues, had some misgivings about this phrase, and were somewhat surprised that within a year ‘human-induced global warming' caught the imagination of much of the world. Indeed today, not a day goes by without some mention of ‘global warming', climate change, emission trading schemes, etc, all terms which up until 1980’s were the preserve of academic text books.

Despite this concern, a colleague of mine from Australia, Bill Kininmonth, who in 2004 wrote a book called "Climate Change - A Natural Hazard" has mentioned to me on several occasions that I have changed from being a ‘gamekeeper' and become a ‘poacher'. Whether that is true is a matter of opinion. However, irrespective of my personal views on the matter, it is clear that there are two main views held by climate scientists and others on the subject of global warming and climate change.

First, those who are mainly involved in the Intergovernmental Panel on Climate Change( IPCC) and many or most government scientists, plus others, such as Al Gore, and many politicians and most journalists who consider that humans activities, including domestic animals, are the prime cause of recent changes in the climate;

Second, those - in the main some university scientists, many retired climatologists, and a minority of politicians and journalists, who consider that “nature” is the main cause of changes in the climate.

Thirty years ago, it was unconceivable that the New Zealand Government would have a Minister of Climate Change; indeed back then, as weather forecasters and climatologists we just got on with our job of making the best possible weather forecast and providing the best climate advice to all those who requested information, without guidance or interference from the Government of the day. How things have changed!

**********

For further information see: https://sites.google.com/images/climatediceandthebutterfly/

The physicist Leo Szilard once announced to his friend Hans Bethe that he was thinking of keeping a diary: 'I don't intend to publish, I am merely going to record the facts for the information of God.' 'Don't you think God knows the facts?' Bethe asked. 'Yes' said Szilard. ‘He knows the facts, but he does not know THIS version of the facts'

"(From Hans Christian von Baeyer, "Taming the Atom" (from the preface paragraph in "A Short History of Nearly Everything", by Bill Brysn, A Black Swan Book, 2004)

****8

https://www.sunlive.co.nz/blogs/13816-solar-activity-and-spotless-days.html

Solar Activity and Spotless Days

The NASA solar physics website, and other websites such as the Royal Observatory of Belgium, include information on sunspot numbers, spotless days, the ‘Maunder Minimum' and sunspot cycle predictions.

A sunspot is a relatively dark, sharply defined region on the solar disc – marked by an umbra, dark area, which is 2000 degrees cooler than the effective photospheric temperature. The average diameter of a sunspot is 4000 km, but they can exceed 200,000 km.

The sunspot index is updated monthly and is available from 1749. The last time the value was much above 200 was in August 1990.

Solar observers have noticed that since mid-2016, the Sun has occasionally been devoid of sunspots. These spotless disks will gradually become a familiar feature as the solar cycle is heading for its next minimum, currently expected by the end of this decade and probably has already started. The number of spotless days can vary significantly from one solar cycle transit to another. For example, during the previous minimum solar cycle 24 (around 2008), 817 spotless days were recorded, whereas the minimum period leading into solar cycle 23 (around 1996) counted only 309 such blemishless days.

The current solar cycle 24 will gradually give way to the new solar cycle 25, and several consecutive days and even periods of 30 or more consecutive days without sunspots will become the norm. the Belgium SILSO website has created a “Spotless Days page”. This page contains graphs and tables on the accumulated number of spotless days, stretches of spotless days, and comparisons to other solar cycles.

The previous minimum (solar cycle 24) surprised many solar scientists and solar observers by being the deepest in nearly 90 years. Will the upcoming solar cycle minimum show as many spotless days, or will solar cycle 25 take off much faster than expected? The “Spotless Days page” provides a front-row seat on the current status of the solar cycle minimum and the number of spotless days. Enjoy!

Since 1849, there have been 114 years (including 2019) with at least one spotless day. The chart below shows the 25 years with the highest number of spotless days. 1913 had 311 spotless days, while 2008 ranks fourth in years with a spotless sun (265 days). With 208 days, 2018 (green bar) has nested itself into the top 25 years with most spotless days.

As of September 22, 2019 there have been 189 days in 2019 without sunspots, and with 100 days remaining in the calendar year, the forecast by many solar scientists is that the 2019 will have over 250 days with sunspots, which would make 2019 the ninth most “spotless” year since records began in 1849.

The ‘Maunder Minimum' is the name given to the period from 1645 to 1715 when the number of sunspots – ‘storms' on the sun – became almost zero. The period is named after the solar astronomer Edward Walter Maunder (1851-1928), who was working at The Royal Observatory at Greenwich when he discovered the dearth of sunspots during this period.

During one 30-year period within the Maunder Minimum there were only about 50 sunspots compared with a more typical 40,000. Maunder was a driving force in the foundation of the British Astronomical Association and a Fellow of the Royal Astronomical Society.The sun was well observed during the period of the Maunder Minimum and this lack of sunspots is well documented. This period of solar inactivity corresponded to a climatic period called the ‘Little Ice Age' when in Europe rivers that were normally ice-free, froze and snow fields remained at low altitudes throughout the year. There is evidence the sun had similar periods of inactivity during the years 1100-1250 and 1460-1550. Sunspots generally follow a cycle of about 11 years, but cycles have varied from eight-15 years.

The connection between solar activity and the earth's climate is an area of ongoing and sometimes controversial research.Time will tell whether the sun will once again go into another ‘Maunder Minimum' within the lifetime of the present generation with very many spotless days , but if this happens we're likely to have a much colder climate for a few decades.

The sunspot number for most days during the last 3 months is zero.

For further information on a range of weather and climate matters see: https://sites.google.com/images/climatediceandthebutterfly/

https://www.sunlive.co.nz/blogs/13788-tropospheric-temperatures-1979-to-august-2019.html

Tropospheric Temperatures 1979 to August 2019

The chart below shows that since 1979, when reliable satellite observations became available, there has been little change in the overall trend in the average tropospheric temperatures, apart from milder/warmer temperatures since about 1997, and two significant warm periods associated with the El Nino events in 1998 and 2015-16.

The latest global average temperatures of the troposphere updated to August 2019 - observed from US National Oceanic and Atmospheric Administration satellites – are computed by the University of Alabama at Huntsville in the United States. The data shows variations from the 30 year period 1981-2010.

Since 1979, NOAA satellites have been carrying instruments which measure the natural microwave thermal emissions from oxygen in the atmosphere. The intensity of the signals these microwave radiometers measure at different microwave frequencies is directly proportional to the temperature of different, deep layers of the atmosphere. Every month, researchers at the University of Alabama (Dr John Christy and Dr Roy Spencer) update global temperature datasets that represent the piecing together of the temperature data from a total of fourteen instruments flying on different satellites over the years.

The graph above represents the latest update; updates are usually made within the first week of every month. Contrary to some reports, the satellite measurements are not calibrated in any way with the global surface-based thermometer records of temperature. They instead use their own on-board precision redundant platinum resistance thermometers calibrated to a laboratory reference standard before launch.

The troposphere is the lowest layer of Earth's atmosphere.

It contains approximately 75 per cent of the atmosphere's mass and 99 per cent of its water vapour and aerosols.

The average depth of the troposphere is approximately 17 km in the middle latitudes.

The coolest months since 1979 were September 1984, with minus 0.49 degrees Celsius, and November 1984, with minus 0.42 degrees Celsius.

The warmest months were February 2016 with plus 0.83 degrees C, February and April 1998 both plus 0.76 degrees Celsius, and March 2016 and April 2016 plus 0.73 degrees Celsius.

The chart shows the El Nino warming in the 1998 period, and 2015-16, and the Mount Pinatubo, volcanic cooling during 1992-1993.

****

In April 2015 Roy Spencer and his two colleagues published the following comment..

Version 6 of the UAH MSU/AMSU global satellite temperature dataset is by far the most extensive revision of the procedures and computer code we have ever produced in over 25 years of global temperature monitoring. The most significant changes from an end-user perspective are (1) a decrease in the global-average lower tropospheric (LT) temperature trend from +0.140 C/decade to +0.114 C/decade (December. 1978 through March. 2015); and (2) the geographic distribution of the LT trends, including higher spatial resolution. See the current webpage for further information.. https://www.drroyspencer.com/latest-global-temperatures/

For further information on a range of climate matters see: https://sites.google.com/images/theweatherclimateeye/

**********

The physicist Leo Szilard once announced to his friend Hans Bethe that he was thinking of keeping a diary: 'I don't intend to publish, I am merely going to record the facts for the information of God.' 'Don't you think God knows the facts?' Bethe asked. 'Yes' said Szilard. "He knows the facts, but he does not know THIS version of the facts'

"(From Hans Christian von Baeyer, "Taming the Atom" (from the preface paragraph in "A Short History of Nearly Everything", by Bill Bryson, A Black Swan Book, 2004)

https://www.sunlive.co.nz/blogs/13764-tauranga-august-average-afternoon-temperatures-19132019.html

https://www.sunlive.co.nz/blogs/13740-tauranga-august-rainfalls-18982019.html

Tauranga August Average Afternoon Temperatures 1913-2019

Temperatures have been recorded in the Tauranga area at several sites in the last 100 years, including the current Tauranga Airport site from June 1990.

The graph shows details of the average daily maximum temperatures, called simply ‘afternoon' for Tauranga for August from 1913-2019. The average for August 2019 was 15.5 degrees Celsius.

The long-term average afternoon temperature in August for Tauranga is 14.8 degrees Celsius. The coolest August months have been 1932 with 13.8 degrees Celsius, and 1941 and 1992 recording 13.9 degrees Celsius.

The warm August months have been 2013 with 16.7 degrees Celsius, and 1915 with 16.4 degrees Celsius, while 2009 had 16.2 degrees Celsius.

The graph of the average afternoon temperatures for August shows generally normal variations from August to August during the last 100 years.

But several recent August months have been a little warmer than others since 1913. This includes August 2013, the warmest on record with a temperature of 16.7 degrees Celsius, which was 1.9 degrees Celsius above average.

From 1913 to 2019, there have been 11 August months with an average afternoon temperature of 15.8 degrees Celsius or more.

Thirteen August months have had an average afternoon temperature of less than 14.3 degrees Celsius.

The sixth warmest August months – in terms of afternoon temperatures – on record in chronological order are: 1915, 1967, 1971, 2009, 2012 and 2013. By contrast, the fifth coolest August months – in terms of afternoon temperatures – on record, in chronological order are: 1932, 1941, 1966, 1992 and 2004.

The average afternoon temperatures during August for the period 1914-1963 were 14.7 degrees Celsius, compared with 15.0 degrees Celsius from 1964 to 2013.

For further information on a range of weather/climate matters see: https://sites.google.com/images/theweatherclimateeye/

Tauranga August Rainfalls 1898-2019

Rainfalls for the month of August have been recorded in Tauranga since 1898, except for 1904, 1907, 1908 and 1909.

From January 1898 to December 1904, the observation site was described as the Tauranga Harbour, from November 1904 to April 1907 the site was described as simply ‘Tauranga'. From January 1910 to December 1923 the site was Waikareao, in Otumoetai; from January 1924 to September 1940 the site was at 148 Waihi Rd, in Judea; from October 1940 to January 1941 the site was at Te Puna; and from February 1941 to now, the site is Tauranga Airport.

The methodology use in adjusting the older sites to the current observing site is published in the ‘NZ Meteorological Service Miscellaneous Publication' No 180 in 1984.

It is considered that the homogeneous rainfall series described here is a fair and true record of what the rainfall would have been if the current observation site (Tauranga Airport) had been used since 1898. This should be coupled with the understanding that although standard accepted methodologies have been used, any adjustments are only estimates of what would have occurred if the location of the rainfall records had always been in the same place with the same surroundings and the same or similar recording gauge.

In terms of climate change (such as is it getting wetter or drier, or warmer or colder), the methodology used in computing an ‘official' set of climate observations is very important, as otherwise erroneous conclusions may be drawn.

The graph shows the range of rainfalls from an extreme high of 274 mm in 2010 to a low of only 17 mm in 1914.

The second wettest August was 1916 when 263 mm was recorded, and the second driest August was in 1982 when only 31 mm fell.

The long-term average rainfall for Tauranga for August is 124 mm. The rainfall for Tauranga for August 2019 was 74 mm.

The graph of the August rainfall shows normal variations from year-to-year.

There is a small decrease in the overall August rainfalls during the last 50 years – from 1961-2010 – from an average of 121 mm, compared with an average of 133 mm during the 50 years from 1911-1960. Since 1898, there have been 11 August months with a rainfall of 220 mm or more – with 10 occurring during 1900 to 1976 – and only one August month since then 2010, which was the highest rainfall for any August. Only five August months have had rainfalls of 50 mm or less.

Chronologically, the 11 wettest August months are 1913, 1916, 1920, 1927, 1938, 1942, 1957, 1965, 1970, 1976 and 2010.

In contrast, chronologically the five driest August months are 1914, 1921, 1982, 1983 and 2002.

For further information see:

https://www.sunlive.co.nz/blogs/13716-global-temperatures-1996-july-2019.html

Global Temperatures 1996 – July 2019