Recent observations show that Beaufort Sea ice was not as it appeared in the summer of 2009. Sea ice cover serves as an indication of climate and has implications for marine and terrestrial ecosystems. 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 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....