Climate Observing System Simulation Experiments

Observations serve a critical role in understanding climate processes, feedbacks and long-term changes. Development of a Climate Observing System Simulations Experiment (COSSE)capability is proposed to help identify key science questions that are observationally limited; evaluate current observations; and estimate the impacts of potentially new observation systems with realistic weather conditions. Key to this approach is that the efforts are hypothesis driven and quantitatively evaluated. Four factors will be simulated for any proposed observation system: temporal frequency, spatial density, accuracy and contributory observations. The work will be carried out under the Quantitative Observing System Assessment Program (QOSAP) framework and in strong coordination with existing weather and ocean OSSE efforts. Key climate questions will be sought from a broad range of climate scientists and will focus on Monitoring the Earth, Advancing Climate Science and Improving Climate Processes. Areas of research will focus on the Grand Challenges identified by the World Climate Research Program: Circulation & Climate Sensitivity; Melting Ice & Global Consequences; Climate Extremes; Regional Sea-level Change & Coastal Impacts; and Water Availability. The COSSE effort will allow the identification of critical climate observations; the evaluation of proposed systems both with respect to their ability to address the challenge and with respect to economic costs; and the promotion of potentially new, innovative observational approaches.