THE NOAA INTEGRATED SURFACE IRRADIANCE STUDY (ISIS) - A NEW SURFACE RADIATION MONITORING PROGRAM

This paper describes a new radiation monitoring program, the Integrate d Surface Irradiance Study (ISIS), that builds upon and takes over fro m earlier NOAA networks monitoring components of solar radiation [both the visible component (SOLRAD) and the shortwave component that cause s sunburn, UV-B] across the continental United States. ISIS is impleme nted in two levels. Level 1 addresses incoming radiation only, and lev el 2 addresses the surface radiation balance. Level 2 also constitutes the SURFRAD (Surface Radiation) program of the NOAA Office of Global Programs, specifically intended to provide radiation data to support l arge-scale hydrologic studies that will be conducted under the Global Energy and Water Cycle Experiment. Eventually, it is planned for level 2 sites to monitor all components of the surface energy balance. Both levels of ISIS will eventually measure both visible and UV radiation components. At present, there are nine sites that are considered to be at ISIS level 1 standard and an additional four level 2 SURFRAD sites . A 10th level 1 site will be in operation soon. Plans call for an inc rease in the number of sites of both kinds, up to about 15 ISIS sites, of which 6 will be at the SURFRAD level. Data are available via FTP a t ftp.atdd.noaa.gov/pub/isis or at http://www.srrb.noaa.gov (level 2).