In last week’s report, we shared our prediction for the Arctic sea ice extent to shift from melting/receding to freezing/expanding. Figure 1 illustrates the changes in the sea ice from then until now. The rate of reduction is actually greater than predicted last week, and the sea ice has only come close to the record minimum coverage observed in 2007 but not exceeded it. However, because we can see a trend of ice coverage increasing from 9 September, the possibility of further reduction is expected to be low. If the sea ice coverage continues to increase, this year’s minimum coverage will be 3.97 million km² as observed on the 9th, making it the second lowest area observed in history.
Currently, both the northeast and northwest passages of the Polar Route continue in an opened state but with ice increasing, ice along the route will spread, too. Both routes are expected to be closed from around late September to early October.

Figure 2 illustrates the progression of the sea ice extent in the Arctic. The sea ice extent for the entire Arctic Sea reached a minimum of 3.97 million km² as of 9 September, and is at 4 million km² as of 11 September almost the same as the extent for the same period in 2007 which is the lowest ever seen. The sea ice extent in the Western Hemisphere (Fig. 2) reached its lowest point in August with 2.30 million km², which is the second lowest following 2.26 million km² observed last year. Meanwhile in the Eastern Hemisphere, the ice extent reached a minimum of 1.65 million km², which is also the second lowest ever seen after the record 1.5 million km² observed during the same period in 2007.
Figure 3 illustrates the current sea ice extent in the Arctic Sea. The Siberian Coast seen on the left side of the illustration shows a trend of shrinkage up to last week. However, it is clear that the ice has started to reaching outward over the last 2~3 days. The Canadian Arctic Archipelago on the right side of the illustration shows no change in particular from last week.

Figure 4 shows possible openings on the northeast (Siberian side) and northwest (Canadian side) of the passage. Although there is a trend of increasing ice, there is no major change in the state of sea ice, so the southern route of the northwest and northeast passages remain open. On the northern route of the northwest passage, the sea ice concentration in Viscount Melville Sound has reduced by 1/10~3/10, and the passage went from red status (ice-breaker escorts required) to yellow (transit possible for ice-strengthened vessels.) However, the route is not yet completely open.

Figure 5 is the prediction model output from Weathernews’ I-See Engine. The sea ice in the Arctic is currently at its minimum level, but we predict that it will gradually progress outward at various points around the North Pole from here. Sea ice along the northeast passage will still be at levels low enough to for the passage to remain navigability for a while longer. However, we expect to see enough ice reappear on the Siberian Coast to close the Polar Route by the end of September.