The coldest ocean
Guess what the name of the coldest ocean is, as the name is Arctic. Half of it is sea (all nine of them), always covered with a moving layer of ice. The surface layer of water (up to 50 metres) has an average temperature of -1.8 degrees, and deeper, where the mass of water practically does not circulate -0.9. Depending on the degree of salinity may vary, but almost always the ocean water close to the freezing point. The Arctic is the smallest (average depth of 1225 meters) and the smallest: size is only 4% of the area of the world ocean and the life it supported by the warm currents of the neighboring areas.
The climate here is very hard: the polar night, the temperature in winter to -30 degrees and in summer around +5 (in sub-Arctic latitudes), permafrost, permanent ice. Year-round lack of sun due to the remoteness of the poles causes severe weather. During the polar night (lasting from 50 to 150 days), when solar radiation is not supplied, all surfaces are cooled only.
In the Central parts of the frozen blocks can reach 5-meter width and do not melt even in summer, this so-called pack ice (multi-year). But some plants, plankton, fish and animals here have adapted well, because cold water contains much more oxygen than warm. It is noted gigantism and longevity of some types (it is home to the largest jellyfish, mussel, squid), due to the slowing of metabolic processes in conditions of low temperatures.
Very negative impact on the Arctic ocean to global warming and pollution by chemicals and oil products. Now the surface area of the ice is 1.5 times less than it was in the 70-ies of the last century. With the mass melting of ice, some species are threatened with extinction : sea lions and polar bears use snow platforms for recreation and hunting. And what is more will increase the reflectivity of the ocean with open water, the faster the temperature rise on the planet Earth….