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 Ångström–Prescott model is reasonably accurate in practice, and the modifications with complex expression are not necessary in Tibet. Then, two general Ångström–Prescott models for estimating the daily and monthly average daily global solar radiation respectively in Tibet are proposed.

► Eight sunshine-based models are evaluated against the measured data in Tibet. ► The simple linear Ångström–Prescott model is reasonably accurate. ► Modifications with complex expression to Ångström–Prescott model are not necessary. ► Two general Ångström–Prescott models for Tibet are proposed.