Noriaki Kimura, Hajime Yamaguchi

Keisuke Nagakawa, Tomoki Fukuma, Keisuke Miyata

1. The Arctic ice extent will show a decrease from last year.

     The minimum extent in September will be about 4.6 million square

     kilometers, which is the fourth smallest.


2. The sea routes of Russian side and Canadian side will both open.

     The Russian side will open around August 25, and the Canadian side

     except for Canadian archipelago will open around July 21.

Figure1:Predicted sea ice cover on September 11, 2015.

Predicted retreat of sea-ice cover shows almost same features as the first report.


On the Russian side, sea ice in the Laptev Sea retreat rapidly. On the other hand, sea ice in the East Siberian Sea is likely to retreat slowly. The sea routes of the Russian side will open around the August 25, which is 4 days later than last year.


On the Canadian side, sea ice retreat more rapidly than usual. The sea routes of the Canadian side except for Canadian archipelago will open around the July 21, which is 11 days earlier than last year.


Overall, the whole Arctic sea ice extent will retreat more rapidly than last two years. Sea ice extent around the September 11, which is the minimal area phase of Arctic sea ice, is expected to be about 4.6 million square kilometers. This is the smallest in these three years, besides the fourth smallest of all the observation.


The predicted minimum ice area is 5% smaller than that estimated in the second report.

Method of Prediction: Difference from the first report

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This prediction used data from satellite microwave sensors AMSR-E and AMSR2. We analyzed the ice motion from December 1 up to April 30, as same as the first report prediction.


In addition to the ice motion, sea ice concentration during June 15-20 is used for the prediction. Sea ice cover in the Arctic starts retreating in May; interannual difference in the shape of ice cover becomes obvious after it. We found that sea ice concentration in June correlates strongly with that after July.


In this report we are showing the predicted ice cover from July 1 to September 11, calculated by the multiple regression analysis based on the ice motion during December-April and average sea-ice concentration during June 15-20 (see the second report of the last year for detailed method).


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In this year, sea ice near the Canadian side retreats rapidly compared with 2013 and 2014. On the other hand, the Laptev Sea ice melts slowly. Though these features agree well with our prediction in the first report, the delay in the Laptev Sea retreat is larger than the prediction. In this updated prediction, the ice cover in the Laptev Sea retreat more slowly than the first report.


2015 summer

Arctic Sea Ice Forecast


Second Report


June 30, 2015

Figure 2:The interannual change of minimum extent since 2003. Value of 2015 is predicted one.

Figure 3:Animation of predicted Arctic ice extent from the 1st of July to the 11th of September. Yellow and green lines indicates the ice edge of 2013 and 2014 .

If you have any questions, please contact H. Yamaguchi or N. Kimura.

This work was partly supported by

GRENE Arctic Climate Change Research Project.

Figure 4:Mean ice concentration during June 15- 20, 2015.

Figure 5:Mean ice concentration during June 15-20, 2014.

Figure 6:Mean ice concentration during June 15-20, 2013.