The rise in global temperatures has led to the melting of the sea ice in polar regions. Scientists have developed a number of computer models that can be used to make predictions about the rate of sea ice melting in these polar regions and its effect on coastal areas globally. In order to create a computer model a number of variables are identified.
A computer model of the effects of the melting of the sea ice in the Arctic Ocean may include the following variables:
- average ocean surface temperature (°C)
- albedo of the ocean (the proportion of light reflected from the ocean surface)
- precipitation (mm)
- salinity of the ocean (grammes of salt in one kilogramme of water)
- area of sea ice (km²)
In this model the following rules have been determined:
- for every 0.01 °C increase in ocean surface temperature, the area of sea ice decreases by 1 %
- for every 1 % decrease in the area of the sea ice, the sea level rises by 20 mm
The initial values are:
- area of sea ice = 1 000 000 km²
- average surface temperature of the ocean is 0.00 °C
For the next iteration, assume there is an increase of 0.04 °C in the ocean surface temperature.
The scientists observed when running the model numerous times using historical data there were significant differences between observed and expected results.
A second model was developed that included new variables and rules.
The surface of the ocean reflects the heat from the sun. The ratio between the area covered by the sea ice and the area where there is no sea ice (open ocean) affects the value of the average albedo. The lower the albedo, the quicker the sea ice will melt.
The average albedo is calculated using this formula: