Revisiting Recent Elevation-Dependent Warming on the Tibetan Plateau Using Satellite-Based Data Sets

Satellite data, characterized by extensive regional coverage and relatively high spatial resolution, have a distinct advantage for examining elevation-dependent warming (EDW) across rugged topography in mountain regions where there are sparse in situ observations. Based on recent (2001-2015) comprehensive satellite-based data sets (2 mair temperature, land surface temperature, snow cover, and daytime and nighttime cloud), this study finds that annual mean 2 m air temperature warming rates show rapid decrease above 4,500 m despite increasing from 2,000 to 4,500 m. This indicates a reversal in EDW at the highest elevations on the Tibetan Plateau, which is somehow different from the EDW derived from short-term land surface temperature presented in earlier research. The decrease of warming rate above 4,500 m coincides with the elevation at which most of the current solid water resources reside. Thus, their decline may be less rapid than previously thought. Trends in nighttime cloud and snow cover are both correlated with patterns of EDW on the Tibetan Plateau, but the leading factor varies on an annual and seasonal basis. These results provide important evidence for understanding EDW and its controlling mechanisms in an extreme high-elevation context.