THE IMPORTANCE OF THE CORRECTION OF PRECIPITATION MEASUREMENTS ON THETIBETAN PLATEAU

Precipitation in the monsoon season on the Tibetan Plateau occurs as r ain or snow depending on the elevation and temperature conditions. Poi nt measurements of precipitation may not describe the accurate spatial distribution if systematic-error corrections of precipitation measure ment are not applied. Precipitation data at 5 points intensively obser ved in the Tanggula basin (33 degrees N, 92 degrees E) were corrected, and the characteristics of the spatial distribution of precipitation are discussed. The largest correction was required for wind-induced lo ss of solid precipitation. The average ratio of corrected and measured precipitation was 1.38. An obvious increase of precipitation toward t he south and higher elevations was found. Three years of precipitation data at two Chinese weather stations located north and south of the T anggula basin were also corrected by the same methods. The ratio of co rrected versus measured precipitation showed a clear annual variation, nearly constant at around 1.2 times in the monsoon season, but some m onths showed increase of more than 1.5 times in the non-monsoon season . Recycling of water between the atmosphere and land surface may stron gly prevail in the Tibetan Plateau, which means that the corrected hig her precipitation amounts directly correspond to a greater evaporation (or sensible heat source).