Validation and Application of Reanalysis Temperature Data over the Tibetan Plateau

The Tibetan Plateau has substantial impacts on the weather and climate of the Northern Hemisphere, due in large part to the thermal effects of the plateau surface. Surface temperature over the Tibetan Plateau is the most important parameter in determining these thermal effects. We present a method for verifying widely used reanalysis temperature products from NCEP-R2, ERA-Interim, and JRA-25 over the Tibetan Plateau, with the aim of obtaining a reliable picture of surface temperature and its changes over the plateau. Reanalysis data are validated against the topography elevation, satellite observations, and radiosonde data. ERA-Interim provides the most reliable estimates of Tibetan Plateau surface temperature among these three reanalyses. We therefore use this dataset to study the climatology and trends of surface temperature over the Tibetan Plateau. ERA-Interim data indicate a dramatic warming over the Tibetan Plateau from 1979 to 2010, with warming rates of 0.33°C per decade in annual mean temperature, 0.22°C per decade in summer and 0.47°C per decade in winter mean temperatures. Comparison with the results of previous studies suggests that surface warming over the Tibetan Plateau has accelerated during the past 30 years. This warming is distributed heterogeneously across the Tibetan Plateau, possibly due to topographic effects.