Many climate models suggest the Arctic ice cover will melt within 50 years. Researchers at Woods Hole Oceanographic Institution want to measure the changes in the water—particularly the layered structure of the ocean—in order to understand what mechanisms might lead the ice cap to melt from below. The impacts for the ecosystem, the regional and global climate, and for commerce would be enormous. Many climate models suggest the Arctic ice cover will melt within 50 years. Researchers at Woods Hole Oceanographic Institution want to measure the changes in the water—particularly the layered structure of the ocean—in order to understand what mechanisms might lead the ice cap to melt from below. But how is it possible to take continuous measurements over long periods of time in such a hostile environment? Scientists and engineers have found a way.