Arctic ice grew slowly in October
November 3rd, 2009 by Jim JustThe National Snow and Ice Data Center (NSIDC) reports that October 2009 had the second-lowest ice extent for the month over the 1979 to 2009 period.
Strong winds from the south over central Siberia helped prevent ice from forming along the Siberian coast. This wind pattern, in conjunction with extensive open water, led to a mean monthly temperature as high as 6 degrees Celsius (11 degrees Fahrenheit) above average in the region between a high-pressure system over the Beaufort Sea and unusually low pressure over the Barents Sea.
NSIDC also reports on a new study by Ian Simmonds and Kevin Keay at the University of Melbourne in Australia, which finds connections between the decline in September sea ice extent and the characteristics of Arctic storms. As ice extent has decreased, Arctic storms have shown a tendency to become more intense, especially in the last few years. The study suggests that low September ice extent, with extensive areas of open water, provides more energy to autumn storms, allowing them to become stronger. The stronger storms also help to break up the ice.
High ice years in the study are 1980, 1983, 1986, 1992, 1996; low ice years are all in the last decade: 2003, 2005, 2006, 2007, and 2008.
Related research at NSIDC reveals that when September ice extent is unusually low, precipitation linked to Arctic storms tends to be greater than when September ice extent is unusually high. Increased autumn snowfall could have effects on both sea ice and permafrost in the Arctic because the snow acts as an insulator that keeps the permafrost and sea ice from thickening.