In early September 2009, satellite measurements implied that most of the ice in the Beaufort Sea either was thick ice that had been there for multiple years or was thick, first-year ice.
However, in situ observations made in September 2009 by Barber et al. show that much of the ice was in fact "rotten" ice -- ice that is thinner, heavily decayed, and structurally weak due to a uniform temperature throughout.
The authors suggest that satellite measurements were confused because both types of ice exhibit similar temperature and salinity profiles near their surfaces and a similar amount of open water between flows. The authors note that while an increase in summer minimum ice extent in the past 2 years could give the impression that Arctic ice is recovering, these new results show that multiyear ice in fact is still declining.
The results have implications for climate science and marine vessel transport in the Arctic.
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Article contains many images of air temperature anomalies, ice measurements for the month of December for the past several years, and more.