Acoustic monitoring of a melting Arctic Ocean.

Abstract

The waters of the Arctic Ocean have been warming since the early 1990s. Average maximum temperatures have risen by more than 1 °C. In the last 20 years submarine measurements of sea ice draft have shown a 40% reduction in average sea ice thickness while satellite remote sensing has shown a 14% reduction in sea‐ice extent over the same period decreasing at a rate of 3%–5% per decade with thicker multi‐year ice at 7%–10% per decade. Forecasts indicate that if these trends continue the Arctic Ocean could be ice‐free in the summer before the end of this century. Significant effort is needed to expand our observational capabilities in the Arctic Ocean to support better modeling, forecasting, and improve our understanding of this critical ocean and the linkages to global climate. One technique acoustic thermometry has been shown to be a very effective for monitoring average heat content and average temperature in the Arctic Ocean and, in particular, in the Arctic Intermediate Water layer. Two experiments conduc...