Pan evaporation modelling and changing attribution analysis on the Tibetan Plateau (1970–2012)

摘要: Pan evaporation (Ep) is an important indicator of water and energy the decline Ep has been reported in many regions over last decades. The climate are dependent on each other. In this study, temporal trends main drivers, namely mean air temperature (Ta), wind speed (u), global solar radiation (Rs), net long-wave radiation(Rnl) vapour pressure deficit (D) from 1970 to 2012, were calculated basis 26 meteorological stations Tibetan Plateau. arithmetic average decreased with rate −11.91 mm a−2; Rs, Rnl, Ta, u D −1.434 w m−2 decade−1, 0.2511 w m−2 decade−1, 0.3590°C decade−1, −0.2376 m s−1 decade−1 9.523 Pa decade−1, respectively. diffuse irradiance essential parameter model quantify contribution climatic factors changing Ep. 60 724 observations Rs (Rd) seven used develop correlation between fraction (Rd/Rs), clearness index (Rs/Ro). On estimation component data, we modified PenPan estimate Chinese micro-pan assess attribution dynamics using partial derivatives. results showed that there was a good agreement observed daily values. decrease mostly due declining (−13.7 mm a−2) some contributions decreasing (−3.1 mm a−2); increase had large positive effect (4.55 mm a−2) total whilst Rnl insignificant (0.35 mm a−2) rates. change result all variables. Copyright © 2014 John Wiley & Sons, Ltd.