This award supports the deployment of ice mass balance (IMB) buoys as part of the Arctic Observing Network (AON) and the Study of Environmental Arctic Change (SEARCH). The autonomous, ice-based drifting buoys measure, delineate and, importantly, attribute thermodynamically-driven changes in the thickness of the ice cover. The IMBs will be deployed strategically and in coordination with other elements of AON to optimize the observation of changes and trends in sea ice throughout the Arctic Basin. The "Broader Impacts" of this award are many. IMB data have and will continue to assist large-scale modeling efforts to improve the treatment of ice growth and decay in GCMs and to assess the relative impact of ice thermodynamics on the observed changes in the Arctic sea ice cover. Results will also provide baseline data to support the development of instruments and algorithms to remotely sense snow depth, ice thickness, and the onset of freeze-up. More generally, this work presents an extraordinary opportunity to capture the attention and imagination of the public and of schoolchildren. The centerpiece of active commitment to educational outreach will be the design and implementation of the "Adopt-a-Buoy" program, where K-12 students will have the opportunity to name and follow a designated buoy after it is deployed in the Arctic. Our participation in a recently funded Integrative Graduate Education and Research Traineeship Program (IGERT), "Polar Environmental Change" with Dartmouth College, will facilitate the involvement of graduate students.