Sunday, May 27, 2012

Arctic Melt-Out Won’t Happen This Year

One summer nearly all the ice that floats on the Arctic Ocean will melt away. That won’t happen without some advance warning, and it won’t happen this year.

The setup for a complete Arctic ice melt will happen in May, with an unusual ice melt pattern that leaves low concentrations of ice in the southern Arctic, so that there is more uncovered water that can soak up the sun during the peak sun season of May, June, and July. That will create warmer sea surface water temperatures to melt away any stray ice that is still around in September.

Ice concentrations in the Arctic Ocean are averaging around 95 percent this month. That is low by historical standards, but enough to mostly protect the ocean from the sun.

Ice concentration is one the best indications of which ice is about to melt, but ice extent is the most reliable way to track how the ice is doing in the long run. The ice extent graph this year so far has been retracing the line from 2010. In that summer, ice extent stayed 10 percent above the all-time low. It gives another reason to imagine that this summer’s melt will be along the lines of what we have seen in the past.