Warm Siberian winds caused October 2009 to have the second-lowest ice extent for the month over the 1979 to 2009 period.
Warm southerly winds during October warmed the Arctic so much that they prevented sea ice from reforming at a rate typical of the previous 30 years.
The U.S. National Snow and Ice Data Center reports that October had the second-lowest ice extent for the month over the period from 1979 to 2009.
The formation of polar ice normally accelerates during that month as the sun sinks lower in the southern sky each day and the day-long nights of winter return above the Arctic Circle.
But the growth rate slowed for a while early in the month as strong winds from the south blew over central Siberia, preventing the ice from forming along the coast there.
By month’s end, expansive areas of open water regions still existed in the northernmost North Atlantic and north of Alaska.