Module #19 - Factors Affecting Climate
NSTRUCTIONS FOR TODAY
1. Watch the following video: Video of the Day: How Climate Classifications are Developed (21 minutes)
Be sure to make point form notes from this video in your digital video journal. Please make sure this document is SHARED with Mr. Durk.
2. Read the following information below in Part 1: Background and Terminology. Follow all hyper-links to external websites for activities, demonstrations and videos (if applicable). Copy only KEY information (i.e. the highlighted terms) to your digital notebook (in google docs). Mr. Durk will be doing a
3. Part 2: Blog Posting: Complete the following on the UG Cloud Blogger.
Choose one of the following cities from the list below (each student must choose a different city), and explain what factors (LOWERN) affect their climate the most. For example, Guelph's climate is mostly influenced by latitude, proximity to the Great Lakes and Winds and Air masses. Guelph's climate is not affected by elevation, relief or ocean currents in any significant way. Provide an explanation for each factor using specific terms and refer to specific bodies of water and mountain chains if applicable.
London, England Sydney, Australia
Paris, France Sao Paulo, Brazil
Vancouver, BC Madrid, Spain
Los Angeles, CA Moscow, Russia
New York, NY Nairobi, Kenya
Tokyo, Japan San Jose, Costa Rica
Hong Kong, China Berlin, Germany
Cairo, Egypt Halifax, Nova Scotia
Dallas, Texas Alice Springs, Australia
Rome, Italy Miami, Florida
4. Part 3: Factors that Affect Climate Activity. Please complete this activity using the paper copies provided to you in class by your teacher.
DUE DATE: Submit all components to Mr. Durk via the UG Cloud before Module #20 (Wednesday May 21st)
Part 1: Background and Terminology
Please remember to record all definitions in your virtual notebook. Definitions can be found by clicking on highlighted words.
Also remember to read and record the concepts presented below in your virtual notebook. This will allow for effective learning.
There are many factors that affect the climate of the Earth. Some factors affect only small regions, whereas others affect the climate of the whole planet. We will divide this activity into four main categories: Earth’s location in space, L.O.W.E.R., volcanic activity and microclimates.
Earth’s Location in Space
At the most basic level, climate is affected by our location in space. Earth is considered to be in a “goldilocks” position in the solar system. This means that it is not too hot, nor is it too cold; scientists also call this the habitable zone. Mars for example, is further away from the sun and has an average daily temperature from -120 to +20. Venus on the other hand has a temperature around 500 near the equator.
The Earth has an average surface temperature of 14 degrees, but ranges from -88 to 50. This allows for water to exist in all three states which is important for life.
L.O.W.E.R. + near water
LOWER is an acronym that stands for five factors that affect the climate of any given area on Earth, and near water is the sixth. Usually places are affected by at least two of these factors, but can be affected by all six. We will look at each of these in depth.
Latitude
As you move further away from the equator in latitude the angle at which the sun strikes the Earth changes. The angle at which sunlight strikes the earth, which varies by location, time of day, and season, is an important factor in the amount of heat energy received at any location on the globe. Seasonal change in the angle of sunlight, caused by the tilt of the earth's axis, is the basic mechanism that results in warmer weather in summer than in winter.
When sunlight shines on the earth at a lower angle, the energy of the sunlight is spread over a larger area, and is therefore weaker than if the sun was hitting the Earth at the equator. If no other factors were involved in climate, then the temperature of the Earth would change at a constant rate the further north or south you went from the equator.
Ocean Currents
The oceans of Earth contain both warm and cold currents. These ocean currents can flow for thousands of kilometers. They are very important in determining the climates of the continents, especially those regions bordering on the ocean. As the current flows near the coast, winds blow across the current and move warmer or cooler temperatures inland. If a warm current is involved, it will also bring increased moisture to coast. Ocean currents can affect areas far inland, as long as there are not topographical barriers.
Canada is affected by three main ocean currents. Eastern Canada including Ontario and Quebec is affected by the warm Gulf Stream current. This has a moderating affect on our climate. The maritime region of Canada is affected by the Gulf Stream and the cold Labrador current. The mixing of the warm and cold currents are what causes the fogs associated with the Maritimes. Finally, British Columbia is affected by the warm Alaskan current which is one of the reasons why the west coast is much warmer, even though it is on the same latitude as Thunder Bay.
Winds and air masses play a large effect on the climate of Canada. Many Canadians live close to the U.S. border, and are affected by both cold air masses from the north, and warm air masses from the south.
Air masses can be divided into categories based on temperature and moisture content.
The temperature characteristics of an air mass are defined by the terms Arctic, Polar and Tropical, with arctic being the coldest and tropical being the warmest. The moisture content of an airmass is defined by the terms Maritime and Continental . A Maritime air is a moist air mass, whereas a Continental air is relatively dry. In Canada our climate is usually affected by warmer air masses during the summer and colder air masses during the winter. This is due to the tilting of the Earth, and helps to give Canada four different seasons.
Elevation
As you increase your elevation the temperature decreases at a constant rate of 6.4 degrees for every 1000m. This is the reason why mountains in tropical areas can have snow all year at their peaks. This drop in temperature is called the environmental lapse rate. The rate does vary with the amount of water vapour in the air.
Relief
This factor of climate is related to elevation, but effects moisture not temperature. Areas near mountain ranges are affected by relief precipitation depending on which side of the mountain they are on. This effect is often called the Rain Shadow effect. This is a dry region on the surface of the Earth that is leeward or behind a mountain with respect to the prevailing wind direction. A rain shadow area is dry because, as moist air masses rise to the top of a mountain range or large mountain, the air cools and water vapor condenses as rain or snow, falling on the windward side or top of the mountain.
This factor mainly affects British Columbia and Alberta.
Near Water
The last factor of climate is the moderating affect of water bodies. Water has a property that it takes longer to heat up and cools down slower than land. This is because water has a high heat capacity. For example, Victoria B.C. is at a higher latitude than Ottawa, but its temperature rarely dips below the freezing mark. The winter season in west coast communities is much shorter than in inland areas. The warmer water can also create increased precipitation because it carries greater moisture. This moisture is then released when the air hits the cooler land. This is a common occurrence in Ontario and in winter is called Lake Effect Snow.
Volcanic Activity
Another factor that can affect the climate of the Earth is volcanic activity.
Large, explosive volcanic eruptions inject water vapor (H2O), carbon dioxide (CO2), sulfur dioxide (SO2), hydrogen chloride (HCl), hydrogen fluoride (HF) and ash (pulverized rock and pumice) into the stratosphere to heights of 40 – 50 kilometres above the Earth's surface. The most significant impacts from these injections come from the conversion of sulphur dioxide to sulphuric acid (H2SO4), which condenses rapidly in the stratosphere to form fine sulfate aerosols. The aerosols increase the Earth's albedo and thus cool the Earth's lower atmosphere or troposphere; however, they also absorb heat radiated up from the Earth, thereby warming the stratosphere. Several eruptions during the past century have caused a decline in the average temperature at the Earth's surface of up to half a degree (Fahrenheit scale) for periods of one to three years.
Photo Credit: U.S. Geological Society
Micro Climates
The last significant factor in any specific location is micro climates. A microclimate is a local atmospheric zone where the climatediffers from the surrounding area. Microclimates exist, for example, near bodies of water which may cool the local atmosphere, or in heavily urban areas where brick, concrete, and asphalt absorb the sun's energy, heat up, and reradiate that heat to the ambient air. Cities often raise the average temperature by zoning, and a sheltered position can reduce the severity of winter.
Another contributory factor to microclimate is the aspect or slope—south-facing slopes in the Northern Hemisphere and north-facing slopes in the Southern Hemisphere are exposed to more direct sunlight than opposite slopes and are therefore warmer for longer.
The most common micro climate created is the urban heat island. The United States EPA says: "On hot summer days, urban air can be 2-10°F [2-6°C] hotter than the surrounding countryside.” What is controversial about these heat islands is whether, and if so how much, this additional warmth affects trends in (global) temperature record. Another result of the urban heat island effect is monthly rainfall that is about 28% greater between 20-40 miles downwind of cities, compared with upwind.
Photo Credit: NASA