The altitudinal dependence of recent rapid warming over the Tibetan Plateau

Abstract

The Tibetan Plateau (TP) exerts significant impacts on its surroundings through its thermal and dynamical processes. In recent decades, especially since 2000, the TP has been experiencing a more rapid warming than its surrounding regions. This study uses Moderate Resolution Imaging Spectroradiometer (MODIS) monthly averaged land surface temperature (LST) product to detect the recent warming trend with respect to elevations over the entire TP, because the number of weather stations from China Meteorological Administration (CMA) is rather limited in the western TP and, furthermore, are unavailable for areas higher than 4,800 m above sea level (ASL). The trend of MODIS LST is first validated against the warming trend estimated from near-surface air temperatures measured at CMA stations and the warming rate dependence on elevation is then derived from MODIS LST. The results indicate that the warming rate increases from 3,000 to 4,800 m ASL, and then becomes quite stable with a slight decline near the highest elevations. This altitudinal dependence of the warming rate has a significant implication for TP water resources and environmental changes, since most glaciers and snow surfaces are located above 5,000 m ASL over the TP.