Dynamical downscaling projections of mean and extreme climate over the Tibetan Plateau under 2 SSP scenarios

Abstract

The Tibetan Plateau (TP) has consistently garnered attention due to its sensitivity to global climate change and the implications of future global warming. This study employs the Weather Research and Forecasting (WRF) model, driven by three global models from the Sixth Coupled Model Intercomparison Project (CMIP6), to investigate future mean and extreme climate changes over the TP. WRF's historical simulation (1995–2014) more accurately reproduces the spatial distribution of temperature, precipitation, and climate extremes compared to global models. Projections suggest that by mid-21st century, under SSP1-2.6 and SSP5-8.5, the TP's average temperature will rise by 1.27 °C and 1.91 °C, respectively, with autumn experiencing the most warming. The western plateau is expected to warm more than the eastern part. Precipitation over the TP is expected to increase, especially in the northwest and central-east regions, by 5%–10%, with winter precipitation increasing by more than 10% under the SSP5-8.5 scenario. Extreme high-temperature events are projected to increase in frequency and intensity, while extreme low-temperature events are expected to decrease and weaken. The intensity and frequency of extreme heavy precipitation events are also expected to rise, mainly in the western and southeastern plateau. Drought events are projected to become less severe in north TP, especially in the Qaidam Basin. The differences between WRF simulations and global models in seasonal and scenario-dependent changes underscore that regional models capture finer regional climate details and reveal limitations in global models. Hence, it is crucial to consider these differences when assessing climate impacts and developing adaptation strategies.