ACE is a new system under continued development, created to meet the need for a decision-support system that will enable long-term Arctic environmental planning, near-term cooperative actions, and real-time responses to humanitarian, environmental, and security issues. Addressing the need for Arctic awareness and research, ACE is a web-based, open-access, Arctic-focused, environmental decision-support system that integrates disparate data from remote sensing assets, models and in situ stations to provide visualization, monitoring, and analysis based on earth observing system data and modeling. This situational awareness tool, based primarily on existing information technology tools, will enable the end user to display, layer, and analyze various remote sensing images, buoy data, near real-time Automatic Identification System capabilities, and sea ice model information for display and interaction via a KML-compliant internet browser. ACE will enable local, regional, and international cooperation and coordination on long-term environmental planning and near-term actions in response to climatic and environmental changes occurring in the Arctic Region.