Seasonal changes in sea ice conditions along the Northeast Passage in 2007 and 2012

Abstract

Remote sensing data from passive microwave and satellite-based altimeters, associated with the data measuredunderway, were used to characterize seasonal and spatial changes in sea ice conditions along the Arctic Northeast Passage (NEP)and the high-latitude sea route (HSR) north of the island groups in the eastern Arctic Ocean in 2007 and 2012. In both years,summer Arctic sea ice extent reached minima since satellite records began in 1979. However, there were large differences inspatial distribution of sea ice between the two years. Sea ice conditions in the eastern sections of the sea routes were relativelyslight in the 2007 summer, because of the remarkable decline of sea ice in the Pacific sector. A belt of sea ice that blocked sectionsfrom the western Laptev Sea to the eastern Kara Sea resulted in both sea routes not completely opening through the 2007 summer.The combination of a great storm in early August causing sea ice to be sheared from the Arctic pack ice and the thick ice survivingthe winter delayed the summer opening of the eastern parts of the sea routes in 2012. However, the average open period, definedby 50% ice concentration for the entire NEP and HSR, reached 82 d and 55 d, respectively. Thus, 2012 was the most accessibleyear since the satellite era began in 1979. The distinct decrease in sea ice in the western parts of the HSR in the 2012 summer canbe attributed to the thinning preconditions of sea ice prior to the melt season. The HSR opening can benefit Arctic shipping ofdeeper-draft vessels.