Global solar radiation estimation with sunshine duration in Tibet, China

Eight models using only the sunshine duration for estimating the global solar radiation on a horizontal surface are evaluated at Changdu, Geer, Lasa and Naqu stations in Tibet, China against the measured meteorological data during 1994-2008. Based on statistical error tests, results show that the simple linear Angstrom-Prescott model is reasonably accurate in practice, and the modifications with complex expression are not necessary in Tibet. Then, two general Angstrom-Prescott models for estimating the daily and monthly average daily global solar radiation respectively in Tibet are proposed. (C) 2011 Elsevier Ltd. All rights reserved