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World map showing location of arctic sea ice

SEA ICE

The polar areas are very important to the overall climate of the Earth, yet there is still a lot for scientists to study in those regions. One of the mysteries still needing more study is sea ice. It is hard to study sea ice because there are extreme conditions in the Polar Regions. Most of the research has been from ships and satellites, with some trips from bases on land masses.

There is sea ice in both the Arctic and Antarctic regions. Both places experience continuous change. In warmer months ice is melting and in colder months it is re-forming. In summer months Arctic sea ice covers about 7 million square kilometers (about the size of the Amazon rain forest!) – and doubles to 14 million square kilometers in the winter months! To give you an idea of the sizes, the continent of Europe is a little more than 10 million square kilometers.

Changes in the Earth’s climate affect sea ice, which is itself something that helps scientists study climate change. Scientists have been taking measurements of ice thickness and how much sea it covers for many years. The fact that sea ice has been decreasing by 2.8% every 10 years since 1978 is a sign that there is climate change around the world. Its thickness varies, from about 2-3 feet thick up to 10-12 feet thick!

Usually people would think that very little life can survive in the extreme cold conditions of sea ice. However, scientists have found numerous and fairly complex plants and animals. They have found “ice algae” and very small animals that feed on these algae. They have also found bacteria, viruses, and fungi.

The sea ice is also used by other animals like the polar bear, which uses it as a platform for hunting and migration. Small plants and animals that survive on the ice floes are food for other marine life. Scientists are also learning more about the links in the food webs between the sea ice and ocean water (in general) and also the ocean floor. We are realizing that sea ice is an important part of the Earth’s ecology!