After five months of melt, Arctic sea ice is near its annual minimum and is tracking at levels close to those recorded a year ago, according to the National Snow and Ice Data Center.
Average August ice extent was the seventh lowest since satellite records began in 1979 -- well below the average rates measured but well above the average August coverage measured in the biggest-melt years, 2012, 2007 and 2011, said the Boulder, Colorado-based center.
Melt rates this August were about normal, in line with a 10.3 percent-per-decade decline seen since satellite records began, the center said.
Annual sea-ice melt usually ends in early to mid-September. Twenty-three forecasts collected last month into an outlook issued by the Arctic Research Consortium of the United States predicted this year's minimal coverage would range from 4 million square kilometers (1.54 million square miles) to 5.6 million square kilometers (2.16 million square miles).
The median of the forecasts was 5 million square kilometers (1.93 million square miles), far above the record low of 3.41 million square kilometers (1.32 million square miles) that was reached in 2012.
As of Thursday, areas of the Arctic Ocean with at least 15 percent ice cover -- the National Snow and Ice Data Center's definition for ice coverage -- was 5.379 million square kilometers, or 2.0768 million square miles. The coverage is similar to levels reported this time last year and this time in 2009, according to the center's records.
The Beaufort and East Siberian seas have particularly low concentrations of ice, and the ice edge has retreated well north of the Laptev Sea, something national snow and ice director Mark Serreze said he has not seen before. But an area of the Barents Sea near Svalbard has above-average ice coverage, according to the center's data.
While there is more ice coverage this year and in 2013 than in the record-breaking 2012 season, there is no evidence of a long-term recovery, Serreze said in an email."The long-term trend remains strongly downward, and we have no reason to think that this trend is going to reverse," he said.
Mariners hoping to sail through the Northwest Passage this summer have been out of luck, according to the center. Much of that route, which runs along the Canadian Archipelago and across the top of North America, has been clogged with ice, the center said. That contrasts with the situation in 2007, 2008, 2010 and 2011, when the anomalous high sea-level pressures kept ice away from the route.
Shipping conditions have been much more favorable this summer along the more Russian-oriented Northern Sea Route, which runs through the Bering Strait and over the top of Asia to Europe, the center said. There are wide areas of open water off the Russian Arctic coast, the center said.