SOLAR RADIATION AT GROUND IN EAST-ASIA FROM DATA OF THE GEOSTATIONARY SATELLITE GMS

A method(Rieland,1985) has been modified to determine the downward solar radiation at ground over East Asia,using GMS-3 data of the satellite with a spatial resolution of 10×10 km2 and a time interval of 3 hours.The distributions of the monthly mean global radiation are obtained for January,April,July and October of 1985.These results illustrate that the topography effect of the Tibetan Plateau is not negligible.The values of global radiation over the high Tibetan Plateau during all seasons are higher than those in the lower-level surroundings.By comparing model results with ground observed data, the relative errors in monthly averages of global radiation are 2.8% for clear sky and 6.3%,5.3%,5.0% and 4.5% for cloudy sky in January,April,July and October,respectively.The relative error in daily global radiation during the snow-free season is less than 20% and larger than 20% in snow-covered winter.We,however,had no data for these comparisons which were measured directly at the Plateau during the year 1985.