Influence of land surface parameters and atmosphere on METEOSAT brightnesstemperatures and generation of land surface temperature maps by temporallyand spatially interpolating atmospheric correction

Tendencies toward desertification or changes of the land surface can be det ected by monitoring land surface temperature (LST), but accurate retrievals require good knowledge of the atmosphere and land surface parameters. Here , the effect of land surface emissivity, LST, and ground height on the erro r of LST associated with atmospheric correction is modeled for the thermal infrared (TIR) channel of METEOSAT using MODTRAN. The atmospheric condition s of midlatitude summer (MLS) and midlatitude winter (MLW) are considered. The results confirm that for accurate atmospheric corrections temperature a nd height variations have to be extended by an emissivity variation. LST ma ps for larger areas are generated using atmospheric corrections derived fro m EMCWF reanalysis and Digital Elevation Model (DEM) data. The corrections are spatially and temporally interpolated using Shepards' method and a mode l of the diurnal LST wave, respectively. The interpolations allow the gener ation of spatially smooth LST maps for any time of the day. Modeling the di urnal wave can partially compensate for the adverse effect of cloudiness an d radiometric noise. (C) Elsevier Science Inc., 2001.