Arctic Sea Ice Forecast

2022 Second report

July 4, 2022
Arctic Sea Ice Information Center, Noriaki KIMURA (Atmosphere and Ocean Research Institute, The University of Tokyo)

The predictions were based on two factors: “sea ice redistribution from winter to spring,” and “accumulated absolute value of sea ice divergence”. The sea ice redistribution was determined from the sea ice movement from December to the end of May, and the accumulated absolute value of the divergence was calculated from daily values for 90 days until the end of May. The “accumulated absolute value of sea ice divergence” is a new parameter to replace “sea ice age” and “mean divergence of sea ice,” which were used in the first report published last month, and is an indicator of the ease of sea ice movement. In areas where this value is large, sea ice is expected to be thin and easy to melt, as it is easy for sea ice to move freely. On the other hand, areas where this value is small are covered by firm, thick sea ice and are less likely to melt. We used this value for this forecast because, based on our analysis of historical data, differences in multi-year ice melting speeds can be considered more accurately than using sea ice age.

The Arctic sea ice extent on September 10, when the sea ice minimum will be about 4.44 million square kilometers. This is greater than in 2020 and less than in 2021. This is also almost same as the first report (about 4.46 million square kilometers).

Summer Arctic sea ice extent has been declining rapidly in recent decades. While the decline was less evident between 2013 and 2019, it declined again significantly in 2020. And on September 10, 2020, the Arctic sea ice extent was 3.77 million square kilometers, the second smallest after 2012. On the other hand, in 2021, sea ice remained from the Beaufort Sea to the Chukchi Sea, and the sea ice extent on September 10 was approximately 4.72 million square kilometers, a significant increase from the previous year. This year’s sea ice extent will be slightly smaller than in 2021 but considerably larger than in 2020, indicating that the sharp decline in 2020 was transitory.

The daily anomaly of the sea ice concentration in Figure 4 shows that sea ice the Russian side will retreat earlier than usual. On the Canadian side, sea ice melting will be slower than usual in July in the area from the Kara Sea to the Beaufort Sea, and more sea ice will remain in the Kara Sea in August and September than usual. This is likely due to the thick and firm sea ice more than 4-year-old extending from the Beaufort Sea to the Chukchi Sea, as seen in Figure 5.