Arctic sea ice sets January record low

The amount of Arctic sea ice set a record low for the month of January, the National Snow and Ice Data Center announced Thursday. 

January 2016 was a remarkably warm month there, the data center said. Air temperatures were 13 degrees above average across most of the Arctic Ocean.

Just before New Year’s, a slug of mild air pushed temperatures above freezing to within 200 miles of the North Pole, according to Weather Underground meteorologist Bob Henson.

This was due in part to a strong negative phase of the Arctic Oscillation for the first three weeks of the month, according to the data center. (The Arctic Oscillation refers to variations in pressure patterns over the higher latitudes of the Northern Hemisphere.)

Sea ice is frozen ocean water that melts each summer and refreezes each winter. It typically reaches its smallest "extent" in September and largest in March of each year, and is tracked by the data center, located in Boulder, Colo.

Measurements of sea ice in the Arctic began in 1979.

The monthly average January 2016 sea ice extent was 42,500 square miles less than the previous record low in 2011.

The lack of ice affects wildlife such as polar bears and walruses and also could be changing weather patterns down here over the U.S.

Though it expands and shrinks each year with the seasons, the overall area of sea ice in the Arctic has been steadily shrinking over the past few decades, due to man-made global warming, according to the National Oceanic and Atmospheric Administration.