Investigating Elevation-Dependent Warming in the Tibetan Plateau through a High-Resolution Dynamic Downscaling

Abstract

The frozen water stored over the Tibetan Plateau (TP) is a vital resource for the people who rely on its meltwater. The current hydrological balance over the TP could alter as global temperatures rise. Further, while the warming rate over the TP appears to experience elevationdependent warming (EDW), the exact rate of EDW at different elevations and projected future EDW rates remain to be determined. In this study, a 9 km high-resolution regional climate model (RCM) simulation was used to analyze EDW for the plateau, along with an evaluation of the model accuracy and an investigation into how the EDW changed spatially and seasonally over the plateau. The method applied for the research was a statistical and visual analysis of the model and the climate station observations. The EDW trend per decade was also illustrated in diagrams, boxplots, and maps. The climate model showed a consistent slight cold bias for the average annual and seasonal mean near surface air temperatures compared to in situ observations. Our findings showed trends of annual average maximum, mean, and minimum temperature exhibited clear EDW over the plateau, with their peak average trend per decade at the 5000-5500 m elevation range. We also found that the EDW is stronger in the simulated minimum temperature than the mean and maximum temperature. For the seasonal EDW, the findings revealed clear EDW for the winter and fall seasons. This study can add to the general knowledge about EDW over the TP and provides further evidence that regional climate models can capture EDW during the cold season over the plateau.