Retrieval and Validation of Surface Long Wave Radiation Budget From CERES

Parameterizations that produce surface radiation fluxes directly from the top of atmosphere fluxes and other meteorological variables are presented. In particular, the techniques employ the top-of-atmosphere measurements made by the CERES instrument on board the TRMM and other EOS satellites (TERRA and AQUA) in combination with other meteorological variables to analyze the energetics of the tropospheric column and surface. The analysis is separated into land and ocean regions. The key parameters derived include, 1) the atmospheric greenhouse effect, in both broadband and window (8 - 12 micron), which is the reduction in the clear-sky outgoing long-wave radiation representing the radiative heating of the surface-atmospheric column, and 2) the back-radiation from the atmosphere to the surface, again in broadband and window, representing the radiative heating of the surface by the atmosphere. The latter parameter is archived in the EOS data base and accessible from the NASA Langley Research Center CERES data archives. The results reported here constitute long-wave model A in the Single Satellite Footprint (SSF) data set. Both the parameters referred to above represent a measure of the atmospheric greenhouse effect. Instantaneous/footprint scale broadband fluxes have been validated against in situ measurements made at the Atmospheric Radiation Program (ARM) Central and extended facilities and at the other surface sites of the Baseline Surface Radiation Network (BSRN) and the Climate Monitoring and Diagnostics Laboratory (CMDL). The agreement is within the stipulated objectives of the broad EOS program. Further analysis of the seasonal and geographical distribution of the surface radiation flux components in the continuum and broadband channels provides observational support for the key role played by the water vapor continuum in modulating the energy balance of the surface and the atmospheric column. Regions with enhanced moisture levels experience a sharp increase in emissions to the surface, especially in the window region which contributes in large part to the enhanced radiative cooling of the surface and the atmospheric column.