NSIDC has just released its August analysis.
Arctic sea ice near record lows
Arctic sea ice extent averaged for August 2011 reached the second lowest level for the month in the 1979 to 2011 satellite record. Both the Northwest Passage and the Northern Sea route appear to be open. Throughout August, sea ice extent tracked near the record lows of 2007, underscoring the continued decline in Arctic ice cover.
Average ice extent for August 2011 was 5.52 million square kilometers (2.13 million square miles). This is 160,000 square kilometers (61,800 square miles) above the previous record low for the month, set in August 2007, and 2.15 million square kilometers (830,000 square miles), or 28% below the average for 1979 to 2000. Sea ice coverage remained below normal everywhere except the East Greenland Sea. In addition, several large areas of open water (polynyas) have opened within the ice pack.
Air temperatures were 1 to 4 degrees Celsius (2 to 7 degrees Fahrenheit) higher than average (relative to the 1981 to 2010 climatology) over the Arctic Ocean (measured approximately 1000 meters above the surface). The strongest anomalies were over the Northwest Passage region. High pressure persisted over much of the central Arctic Ocean, associated with a wind pattern that helped to push ice from the Beaufort Sea westward into the Chukchi Sea. This may have slowed some ice loss in the Chukchi Sea region. However, the wind pattern also transported ice into open waters warmed during the summer, fostering melt.
Sea ice is now almost completely gone from the channels of the Northwest Passage, with the exception of a small strip of ice across a stretch of the Parry Channel. The southern route (Amunden's Route) is ice free. According to the Canadian Ice Service, sea ice extent in the western Parry Channel is now the lowest at this time of year since record keeping began in 1966 and very little multi-year ice remains. According to Multisensor Analyzed Sea Ice Extent (MASIE) data, ice cover across the Canadian Archipelago is at record low levels.
The Northern Sea Route along Siberia remains ice-free, with a number of cargo ships passing through in recent weeks. However, some areas of older, thicker ice have helped preserve the tongue of ice extending into the East Siberian Sea.
Will Arctic sea ice extent reach a new record in 2011?
The melt season for Arctic sea ice will soon draw to a close. Surface melt has already largely ended and the ocean waters are cooling. Air temperatures at the North Pole have fallen below freezing. However, with the ice cover now thinner than in years past, there is a greater potential for late-season ice loss, caused by warm water melting ice from below or winds that push the ice together.
Whether Arctic sea ice breaks a new record hinges on three factors: First, how much heat is left in the ocean to eat away at the ice edge and bottom? Second, will wind patterns blow the ice together and reduce ice extent or will they disperse the ice and expand ice extent? Finally, just how thin is the remaining ice cover? Thin ice quickly melts away when it is surrounded by warm water.
Read the whole report HERE.