| Observable changes with regional and global implications, such as warming temperatures and decreases in sea ice, are taking place throughout the Arctic. However, because observations and measurements of these changes are incomplete and not well coordinated, it is difficult to provide a comprehensive description of current conditions, let alone to understand the connections of these changes to the rest of the Earth system. The National Science Foundation, through its Office of Polar Programs, asked the National Research Council for guidance in designing a pan-arctic observing network. This report outlines the potential scope, composition, and implementation strategy for an integrated, dynamic, multidisciplinary, environmental arctic observing network (AON) that would improve our understanding of and ability to respond to systemic changes in the Arctic and anticipate, predict, and respond to future changes in the Arctic and around the globe. Building on existing national and international networks, AON would be a system of observational infrastructure (satellites, terrestrial observatories, ocean buoys and moorings, weather stations, hydrologic monitoring stations, ecological sampling networks, arctic residents, and other data sources) that collects, checks, organizes, and distributes observations and is capable of continuous adaptation and improvement. Because many potential components of the network already exist or are being planned, and because of the surge of activity during the International Polar Year, there is an immediate opportunity for making substantial progress. |  |