Estimation of atmospheric transmissivity of solar radiation from precipitation in the Himalaya and the Tibetan Plateau

Though solar radiation is important for glacier mass-balance simulation, solar radiation data are not always available. As a result of analyzing meteorological data measured in the Himalaya and the Tibetan Plateau, a favorable correlation between precipitation and atmospheric transmissivity of solar radiation is found in terms of monthly values. Monthly mean solar radiation is derived from the relationship between atmospheric transmissivity of solar radiation and precipitation with input of monthly precipitation, latitude, skyline and time. The differences between estimated and observed monthly mean solar radiation are −2 in most cases. However, the differences at some sites are significantly large. The error in the estimated solar radiation during the monsoon season can be large when the monthly mean precipitation rate is about 5 mm d−1. Though the error in the estimated solar radiation during the non-monsoon season is generally small due to low precipitation in the Himalaya and the Tibetan Plateau during this season, it can exceed 100 W m−2.