Plans for an Observational Analysis of the Variations of the Global Energy and Water Cycle

Through the efforts of an international array of national agencies and university research groups, coordinated by the Global Energy and Water-cycle Experiment Radiation Panel, a detailed observationally-based description of the weather-scale (3-hourly, 100 km) variations of the global energy and water cycle over more than a decade is nearing completion. This data collection quantifies in a physically consistent way the variations of the atmosphere (temperature, humidity, winds, clouds, aerosols), the surface (temperature, albedo, snow cover, sea ice cover) and the fluxes of energy and water between the surface and atmosphere (including evaporation, precipitation, sensible heat and radiation) and the radiative fluxes between the atmosphere and space. Most of these data products are based on satellite observations, supplemented or anchored by measurements by organized surface networks. More recent satellite missions using a variety of sensors are developing descriptions of the vertical profiles of these fluxes in the atmosphere. Other coordinated efforts are compiling similar information about the ocean. A diagnostic study of the energy and water exchanges during Madden-Julian Oscillation events is presented to illustrate the kinds of analyses that are now possible with this data collection. In particular, global analysis of this data collection should advance our understanding of the “fast” climate feedback processes which are the same ones that operate during transient variations of the global energy and water cycle.