Satellite-derived surface radiation fluxes at the ARM SGP and TWP Manus CART sites

Surface-measured radiative fluxes are important inputs to climate models, but have minimal areal coverage. The analysis of spatially and temporally appropriate satellite data in conjunction with radiative transfer model calculations and empirical techniques can extend the coverage of surface fluxes. The visible infrared solar-infrared split window technique (VISST) uses satellite data taken at four wavelengths (0.65, 3.9, 11, and 12 um) to retrieve cloud properties and radiation parameters at a nominal 4-km resolution over the Atmospheric Radiation measurement (ARM) Southern Great Plains (SGP) and Tropical Western Pacific (TWP) sites. VISST derived top of atmosphere (TOA) albedo and outgoing longwave radiation (OLR) data in addition to vertical profile data and climatological values of ozone and aerosol optical depth are used as input into three different algorithms to calculate surface shortwave and longwave fluxes for each site. Satellite-derived surface fluxes using observed values of ozone and aerosol optical depth are also be calculated. Since the accuracy of the satellite-derived surface fluxes depends on the quality of the input parameters, both sets of satellite-derived fluxes will be validated with surface flux observations over the SGP Central Facility and the TWP Nauru sites to determine the model sensitivity to the ozone and aerosol optical depth. These near-real time flux parameters are being derived every 30-minutes to 1 hour over the United States and the TWP.