Comparison of Radiation Computations Using Observed and Estimated Precipitable Water

Abstract

Hourly values of total solar radiation are computed by two methods at 11 stations in all regions of the United States for a two-year period. In the first method, precipitable water is computed from radiosonde observations while in the second method it is estimated from surface dew point. Annual differences were 1% or less at 10 of the 11 stations and less than 2% at all stations for both years. Differences in individual months were also less than 2% at all stations with few exceptions.