Currents move water from place to place in the world's oceans. They are controlled by wind, gravity and temperature, which causes water to rise to the surface, or sink to the depths. Several submarine ridges interfere with the currents between the Arctic and Atlantic Oceans, causing a large pool of stagnant, cold water to be trapped on the bottom of the Arctic Basin. Only surface water is able to flow freely in and out of the Arctic.
The Beaufort Gyre current slowly rotates Arctic waters and is responsible for the turning of the Polar Ice Cap. It takes four years for the cap to make one full rotation. The Transpolar Drift Stream transports the cold water of the Arctic eastward across the pole and past Greenland into the Atlantic. The largest outflow of arctic water is on the North Greenland Current, whereas the largest inflow of warm water comes from the North American Current from the Atlantic Ocean.
One of the most important factors that influences temperature is solar radiation. Thus, temperature in the Arctic is directly affected by the season, whether it be winter when there is little or no sun, or summer when the ice cover reflects 90 percent of the sun's radiation. Even when the land is warming, the temperature over the Arctic Ocean is around zero. The National Snow and Ice Data Center explains, "this occurs because the sea ice cover is at its melting point, which keeps air temperatures near freezing."
The Arctic is covered with ice and snow, which reflects most of the sun's energy away from the earth. However, the National Oceanic and Atmospheric Administration (NOAA) reports, "Sea ice and permafrost are decreasing, precipitation patterns are changing, the air is warmer, and the intensity of harmful UVB radiation is increasing." This melting ice could change the amount of the sun's energy that is absorbed by the Arctic. Sea levels could increase, changing the currents of the world's oceans.
NOAA reports that over the last 30 years, warming temperatures in Alaska and Europe are indicators that the Arctic is changing. The circulatory pattern of the world's oceans is what keeps the world's temperatures consistent. Changing sea ice conditions, whether from the ice and snow cover over the Arctic ocean melting or from changes in other ocean currents, will change heat distribution over the entire earth. NOAA states, "Thus the climate in the mid-latitude belt depends significantly on natural processes in the Arctic."
