Arctic sea ice second lowest on record

ALAN BAILEY

Petroleum News

The National Snow and Ice Data Center has reported that the extent of the Arctic sea ice cover probably reached its minimum for the year on Sept. 10. Following cool, stormy and cloudy weather over the Arctic Ocean during the summer, conditions that are thought to limit the rate of Arctic sea ice loss, warm weather in early September, especially along the Siberian coast, accelerated the ice melt.

The result was a minimum ice extent that tied with the minimum observed in 2007 as the second lowest on record. This year’s minimum of 1.6 million square miles was 290,000 square miles above the record minimum extent of 1.31 million square miles, observed in 2012.

The minimum extent was well below the average for the period since satellite observations of the ice began 37 years ago.

Satellite data suggest that the southern Northwest Passage sea route is open. However, the Northern Sea route around the north coast of Russia may be blocked by scattered sea ice near the Taymyr Peninsula, NSIDC says.

The cruise ship Crystal Serenity recently completed a sightseeing cruise through the open waters of the Northwest Passage.

NSIDC suggests that an especially thin ice pack in the Arctic Ocean at the end of last winter may have played a significant role in the low ice minimum in September. The winter ice maximum extent in 2016 hit a record low in March, with relatively low ice extents continuing into June. But there is little statistical correlation between the winter maximum extent and the fall minimum extent, NSIDC says. The rather warm upper ocean water in the Arctic during the summer, coupled with the thin ice, may have contributed to the low ice extent in September, NSIDC suggests.

The greatest late-season ice loss appears to have taken place in a large area of patchy ice extending from the eastern Beaufort Sea to the northern Chukchi Sea, a region impacted by a couple of intense summer cyclones. Strong winds associated with these storm systems may have compacted the ice cover while also driving an upward mixing of warm ocean water, NSIDC says.