THE RESEARCH AND CALCULATION OF SURFACE ALBEDO OVER TIBETAN PLATEAU FROM SATELLITE DATA

Surface albedo is an important factor of climate system. Tibetan Plateau is a sensitive area to climate. Accurating deriving the surface albedo will be very helpful to numerical simulations and climate research. But it's almost impossible to get a succession of high resolution surface parameters over the whole Plateau with conventional observation.After doing the discrimination among cloud,snow and snow-free land,a 9-daycomposing method to extract clear sky planetary albedos over Tibetan Plateau (20-45°N,75-100°E) is used. And then to calculation monthly mean surface albedos. One year data of 1992 have been processed.Some conclusions can be drawn as following:(1)It's feasible to derive surface albedo over Tibetan Plateau from satellite data.The retrival results are trust worthy.(2) The results of the derived surface albedos fit the natural ground feature perfectly.(3)The variations of the surface albedos are dependend on months and seasons.(4) The change of the snow cover has a notable effect on surface albedos.