Low Arctic Winter Ice; Polar Region Experiences Ozone Loss

The maximum extent of winter sea ice in the Arctic, reached earlier this month, tied for the lowest maximum ever measured, according to the National Snow and Ice Data Center (NSIDC) at the University of Colorado. This year, maximum sea ice extent in the Arctic reached 5.65 million square miles, roughly 460,000 square miles below the 1979 to 2000 average. That maximum matches the previous record low maximum, set in 2006. Walt Meier, a research scientist at the NSIDC, said one reason for this year’s lower sea ice maximum is that autumn sea ice growth is increasingly delayed by rising Arctic temperatures, meaning ice extent is not able to “catch up” in winter. Meanwhile, scientists report that protective ozone in the upper layers of the Arctic atmosphere has been reduced by about half this year and that the Arctic, for the first time in recorded history, may experience an ozone hole similar to the one over the Antarctic. Ozone is destroyed by chlorofluorocarbons and other chemicals, and destruction intensifies as temperatures in the stratosphere decrease. Scientists say that heat trapped at lower levels by greenhouse gases may be making the stratosphere colder. Low-ozone air from the Arctic may drift as far south as New York this spring, possibly increasing risks of skin cancer.