Oldest and Thickest Arctic Sea Ice Endangered

Nature Communications, January 4

The oldest and thickest portions of Arctic sea ice can be found in the Nares Strait, located off the northwest coast of Greenland.  Sea ice tends to form in the Laptev Sea north of Russia, then circulates around the Arctic Ocean, with thick multi-year ice discharging each summer through the Nares. Typically, sea ice arches form every winter at the northern and southern ends of the Strait, holding this thickest ice in place and preventing its discharge south to warmer latitudes and eventual melt until the next summer.  These ice arches thus play the role of gatekeeper in preserving thick multi-year ice. However, new satellite imagery reveals that sea ice along the Strait is becoming more unstable, with ice arches slower to form, and a recent increase in changes of both ice area and volume. In addition to threatening a vital last refuge for ice-dependent species and traditional activities for indigenous communities, the potential loss of this multi-year sea ice in the Nares may impact overall loss throughout the Arctic Ocean, by speeding up discharge of multi-year ice.

https://www.nature.com/articles/s41467-020-20314-w

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