MOSCOW, July 19. /TASS/. The ice cover in the Barents and Kara Seas may become a seasonal phenomenon, which will be observed only in winter months. This phenomenon may become a typical condition during the current decade already, an expert of the Lomonosov Moscow State University’s Geographic Department Vladimir Ivanov told TASS.
"Some marginal Arctic seas may become seasonally ice-free in summer already during the current decade. First of all, those are seas of the Atlantic Arctic: the Barents and Kara seas. This trend began to develop after 2007, when those seas remained completely cleared of ice for long periods during the summer seasons. At the same time, in the year of the record minimum ice cover (2012) in summer, all the Siberian shelf marginal seas were completely free of ice for one or two weeks," the expert told TASS.
The researcher clarified that in winter "the ice in the Arctic will not disappear". At the same time, the Arctic Ocean may become completely ice-free for a period of more than one month in summer, according to experts, by 2080-2100, depending on how intensive greenhouse gas emissions will be.
"The duration of the ice season gets shorter due to later freezing and earlier ice opening. Generally speaking, in various Arctic regions, freezing begins 12-15 days earlier per every decade, and earlier ice opening tends to begin 5-8 days earlier per every decade," he said. "However these figures vary greatly depending on the geographical area."
The expert named main factors contributing to the ice cover reduction in the Arctic. One of them is "the Arctic strengthening", which results in the growing speed of the air temperature warming in the surface layer in that region. It is about by 2.5 times higher than the average planetary value. Another factor is the vertical mixing, due to which the upper layers of water are "heated" due to warmer layers deep in the ocean, the scientist said.