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Ice, Ice & More Ice
Factfile |
 Ice, Ice & More Ice |
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Sea Ice |
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Beyond the ice shelves is the sea and Sea ice is the general term for any form of ice found at sea which has originated from the freezing of sea water (Sea ice includes grease ice, pancake ice, pack ice and frazil ice)
Sea Ice
Each winter, the sea-ice around Antarctica grows to roughly twice the size of the continent. Although Antarctica sea-ice varies every year - it changes from approximately 3,000,000 square km in the spring to 20,000,000 square km in the winter - an area twice the size of Europe!
Antarctica's Sea Ice is very important for two major reasons:
Firstly, it has a direct affect on the marine ecosystem in Antarctica. When the sea ice melts each spring, there is a sudden blooming of microscopic plants (phytoplankton) which drift in the ocean currents. These plants thrive on the surface of the Southern Ocean as a result of the ice melting and make up the food for many small marine animals like krill and so the Antarctic food chain begins.
Antarctica's Sea Ice affects the weather patterns of the whole Southern Hemisphere as it acts like an insulating blanket over the Southern Ocean by stopping it from absorbing light and heat from the Sun. Sea Ice and the snow on top can filter out 99% of the light. As a result the presence of sea ice keeps the air cool and dry in Antarctica and then when the ice melts, it cools down the ocean and the atmosphere.
Most scientists agree that global warming is having a huge effect on the polar regions as the amount of ice covering the Southern Ocean has decreased. If the amount of sea ice decreases, the Southern Ocean can absorb more heat from the Sun. This makes the temperature still higher, so more ice starts to melt and so you have a circle of consequences.
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