Nussbaumer, EA; Pinker, RT (2012). Estimating surface long-wave radiative fluxes at global scale. QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, 138(665), 1083-1093.
A new approach for calculating downwelling surface long-wave radiation (DSLW) under all sky conditions is presented. The DSLW model (DSLW/UMD) is driven with a synthesis of the latest 1 degrees resolution Moderate-resolution Imaging Spectroradiometer (MODIS) level-3 cloud parameters and information from the European Centre for Medium-Range Weather Forecasts (ECMWF) ERA-Interim model. The DSLW/UMD's clear-sky contribution is based on the Rapid Radiative Transfer Model (RRTM) and is globally applicable, while a statistical cloud structure model and parametrization determine the cloud contribution to DSLW. Daily averaged estimates of DSLW for 20032007 along with four commonly used methods based on radiative transfer (RT) theory are compared against ground measurements from the Baseline Surface Radiation Network (BSRN). It is shown that for all four years, the proposed approach performs as well as or better than the available RT-based models when evaluated against BSRN measurements. Correlation coefficients, absolute value of bias (W m-2), and RMSE (W m-2) are 0.973 to 0.974, -0.07 to 1.9, and 16.82 to 17.35, respectively. When stratified into Tropical, Midlatitude, and Polar latitudinal belts, largest discrepancies against ground observations are found at high latitudes. Copyright (c) 2011 Royal Meteorological Society