by David Middleton, September 26, 2018 in WUWT

Anthony recently posted an excellent Arctic sea ice analysis by Ron Clutz.  In a similar vein, I decided to look at Arctic sea ice from a couple of other dis-alarming perspectives.

We keep hearing about the Arctic being ice-free anytime from next month up until a continuously rolling forward decade or so.  One question that has to be answered is:

What does ice-free mean?

When does ice-free mean ice-free?

First, we need to clarify what exactly an “ice-free” Arctic summer is.

By “ice-free”, scientists usually mean a sea ice extent of less than one million square kilometres, rather than zero sea ice cover.

–Dr Alexandra Jahn, Assistant Professor in the Department of Atmospheric and Oceanic Sciences and Fellow at the Institute of Arctic and Alpine Research at the University of Colorado. Carbon Brief, August 25, 2016.

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