Over the past several decades, the Arctic Ocean has undergone substantial change. Enhanced transport of warmer air from lower latitudes has led to increased Arctic surface air temperature. Concurrent reductions in Arctic ice extent and thickness have been documented. The first evidence of warming in the intermediate Atlantic Water (AW, water depth between 150 and 900 meters) of the Arctic Ocean was found in 1990. Another anomaly, found in 2004, suggests that the Arctic Ocean is in transition toward a new, warmer state [Polyakov et al., 2005, and references therein].