The Arctic as a "Heat Sink"
The Arctic plays a key role in the earth's heat balance by acting as a "heat sink." The global earth-atmosphere system gains heat from incoming solar radiation, and returns heat to space by thermal radiation. Most of the heat gain occurs in low latitudes, and this gain is balanced (on average) by heat loss that takes place at latitudes north and south of about 40 degrees. Therefore the Arctic is said to act as a "heat sink" for energy that is transported from lower latitudes by ocean currents and by atmospheric circulation systems.
Heat is transported to the Arctic primarily in the following ways:
Sensible heat is transported poleward during the exchange of air masses from the tropics to the middle and high latitudes. This transfer of heat is largely accomplished by cyclones.
As storms travel poleward, some of the water vapor condenses as clouds, thereby releasing latent heat.
Ocean currents bring heat from the tropics to the the northern part of the Atlantic Ocean and into the Arctic.