What Is The Global Energy And Water Experiment (GEWEX)?

Under GEWEX, the study of the radiation exchanges in the climate system combines ISCCP with a project to determine the global Surface Radiation Balance (SRB) from satellite observations, anchored by accurate, long-term measurements at the Baseline Surface Radiation Network (BSRN) sites, with projects to determine the global distribution and radiative effects of aerosols, the Global Aerosol Climatology Project (GACP) and the Stratospheric Aerosol and Gas Experiment III (SAGE III), and other investigations of radiative modeling organized by the GEWEX Radiation Panel (GRP), including the Intercomparison of Radiation Codes in Climate Models (ICRCCM) and the International Intercomparison of 3D Radiation Codes (I3RC) projects.

These studies also make use of data from a continuing series of satellite experiments to determine the radiation budget at the top of the atmosphere (the NIMBUS-7 Earth Radiation Budget, the Earth Radiation Budget Experiment (ERBE), the Scanner for Radiation Budget (ScaRaB), and the Clouds and the Earth's Radiant Energy System (CERES)).

The study of the global water cycle combines ISCCP cloud data with projects to determine the global distribution and variations of precipitation, the Global Precipitation Climatology Project (GPCP), augmented by the experimental Tropical Rainfall Measuring Mission (TRMM), the distribution of water vapor, the Global atmospheric water Vapor Project (GVAP), and of the fluxes of water and heat at the ocean surface (SeaFlux).

The key modeling study to understand how atmospheric motions determine the properties of clouds and the formation of precipitation is carried out under the GEWEX Cloud System Study (GCSS), and the GEWEX Global Land/Atmosphere System Study (GLASS).