The extent of sea ice in the Arctic has been declining twice as fast in the past 20 years as it did during the period 1979-1999. This is one of the most striking manifestations of climate change on the planet. At the same time, there are non-linearities and differences in the dynamics of processes in the Arctic regions in different periods. This conclusion was made by climatologists of the Institute of Geography of the Russian Academy of Sciences.
Russian geographers have identified two periods that are fundamentally different in terms of the rate of ice melting – 1979-1999 and 2000-2019. A regional analysis of the changes that have taken place revealed that in the Barents Sea during the cold season in the past 20 years, the area of sea ice began to decrease twice as fast as in the last two decades of the last century. A significant increase in the rate of ice melting was also observed during the warm period in the Kara, Laptev, East Siberian, Beaufort seas, in the Central part of the Arctic south of 80 ° N. sh., as well as in the North-Western straits of the Canadian Arctic Archipelago.
At the same time, the decrease in the area of sea ice in the Arctic as a whole occurred at the maximum rate in August-October (860–880 thousand km2 for 10 years). From December to April, up to 80% of losses in the entire Arctic region were due to the reduction of ice fields in the Barents and Okhotsk Seas. In June-July, the Kara Sea, the Laptev Sea, and the East Siberian Sea played a decisive role in changing the trend. In August-October, the main contribution was made by the Central Arctic south of 80°N. sh. and the East Siberian Sea. In November-December, the most significant were the reductions in the area of ice in the Barents, Kara, Baffin Seas and in the Hudson Bay.
The authors of the study believe that the accelerated melting of Arctic sea ice at the beginning of the 21st century may be due to human activities and an increase in the amount of greenhouse gases in the atmosphere. Also, the process may reflect the transition to a new dynamic state of the entire Arctic climate system, when heat transfer to the Arctic from the ocean and atmosphere increases and positive feedback is activated in this system.
The scientific work of specialists from the Institute of Geography of the Russian Academy of Sciences Tatiana Matveeva and Vladimir Semyonov was published in the journal atmosphere.