Completed Report

Sea Ice

Introduction

The sea ice in the Arctic plays an important part in regulating the Earth's overall temperature. By reflecting back the energy from the Sun, the ice helps to lower the overall temperature of the Earth. If this ice was to disappear, the Earth would end up reflecting less of the Sun's energy back and hence would warm up the planet. This would in turn cause land ice to melt and would raise the overall sea level.

People who live in low lying areas are concerned about the rise of sea levels as they are worried about their homes flooding. “Even a modest rise in sea levels could cause flooding problems for low-lying coastal areas.”1

Purpose Statement

I am going to forecast the amount of sea ice in the Arctic over the period Jan 2018 - Dec 2019 in the National Snow and Ice Centre Dataset. I will use my forecasts for Arctic sea ice to make an inference about sea levels in the Pacific Ocean and its effects on the flooding of coastal areas in Pacific Islands.

1. http://science.howstuffworks.com/environmental/green-science/global-warming4.htm

Purpose

Data

The sea ice is the surface area of sea ice in the Arctic Circle which is measured in millions of square kilometres.

The data used in this investigation is from the National Snow and Ice Data Center from 1990 - 2011.

Analysis

Appropriate displays used.

Axes labelled correctly

By looking at the long term trend, I can see that overall the amount of sea ice in the artic appears to be generally decreasing from an average of about 9.45 million square kilometres in 1990 to an average of about 8.37 million square kilometres in 2011.

This is an average decrease of (9.45 - 8.37)/21 = 51,000 square kilometres per year.

This decreasing trend appears to be quite constant, apart from a slight trough between 1995 and 1996.

Features described: Long Term Trend

Appropriate displays used

The largest amount of sea ice at the North Pole normally occurs during February and March when the amount of sea ice is approximately 4 million square kilometres above the long term trend. Between April and August there is a consistent drop from month to month as temperatures are rising. The smallest amount of sea ice regularly occurs in September where the amount of sea ice is approximately 5 million square kilometres below the long term trend. After this the temperatures start cooling down again increasing the amount of ice on a month to month basis until it returns to its peak in February and March.

Features described: Seasonal Pattern

Absolute Highest Value: 14, Absolute Lowest Value: 3. (14-3)/10=1.1

Looking at the residuals graph there in only one point that is more than 1.1 million square kilometres away from the trend. This occurred in September 2007 and may have been due to an unusually hot summer.

Features described: Outliers

Appropriate displays used

Overall the model seems to fit the data very well. Most of the fitted values match up with the raw data, however there does appear to be an increase in the difference since 2008 which may be due to an increase in climate change altering the pattern.

Appropriateness of the Model

In April 2011 I would expect the amount of sea ice for the Artic to be 11.69 million square kilometres. However I cannot be completely certain about my prediction, but I would expect the area of ice will between 11.11 million square kilometres and 12.27 million square kilometres.

In March 2013 I would expect the amount of sea ice for the Artic to be 12.44 million square kilometres. However I cannot be completely certain about my prediction, but I would expect the area of ice will between 9.53 million square kilometres and 15.35 million square kilometres.

We can’t be completely certain about our predictions as there are a number of factors that could be affecting the amount of sea ice. One of these factors is possibly global temperatures which is affected by sun spots.

Confidence in Predictions

Conclusion

In conclusion, there appears to be a definite decrease in the amount of sea ice at the North Pole. An average decrease of 51,000 sq km per year is a substantial amount. This should be of concern to people living in low lying areas as this means the sea ice levels are likely to be rising, potentially putting their homes at risk of flooding.

Summarise and Link Back to the Purpose

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