Arctic sea ice ecology and history

September 2, 2012 (The record lowest minimum ever observed in the satellite record occurred on September 16, 2012, when sea ice plummeted to 3.41 million square kilometers (1.32 million square miles). This image shows the area two weeks earlier).

January 1, 2013 through September 10, 2016, the date when the sea ice reached its annual minimum extent.

Satellite views of Arctic sea ice.

The Arctic sea ice covers less area in the summer than in the winter. The multi-year (i.e. perennial) sea ice covers nearly all of the central deep basins. The Arctic sea ice and its related biota are unique, and the year-round persistence of the ice has allowed the development of ice endemic species, meaning species not found anywhere else.

There are differing scientific opinions about how long perennial sea ice has existed in the Arctic. Estimates range from 700,000 to 4 million years.