South Asian cross-border aerosols play a critical role in the climate change of the Tibetan Plateau (TP). While previous studies have investigated the transboundary transport of these aerosols primarily from a tropospheric perspective, there is still no systematic understanding of the linkage with anomalous stratospheric polar vortices. To address this gap, this study explores the potential linkage between sudden stratospheric warming events (SSWs) and transboundary aerosol transport from South Asia to the TP during 1984—2021 using reanalysis and observational datasets through composite analysis. The results show that both the vortex displacement-type and split-type SSWs are likely to decrease the cross-border aerosol transport from South Asia towards the TP. For vortex displacement-type SSWs, from day 0 to day 20 relative to the onset date, an anomalous anticyclone extends from the Persian Gulf towards northern China at 500 hPa and 300 hPa. Northeasterly anomalies dominate over the southern TP and northwestern South Asia at 500 hPa and 300 hPa, impeding the transport of aerosols from South Asia towards the TP. For vortex split-type SSWs, an anomalous anticyclone anchored over the Iranian Plateau induces persistent easterly anomalies across the southern TP and northern South Asia at 500 hPa and 300 hPa from day 10 to day 20 following the onset date of vortex split-type SSWs, hindering the transport of aerosols from South Asia towards the TP. This study not only deepens our understanding of climate change over the TP, but also has profound implications for protecting the ‘Third Pole’ and ensuring its ecological and water resource security.

Arid and semi-arid regions constitute approximately one-third of the total land area in China and are vulnerable to the effects of global climate change. Over the past century, a large number of studies have investigated regional climate change and its impacts. However, the conclusions are inconsistent due to differing research perspectives, and this has highlighted the urgent need to obtain systematic, scientific knowledge through review and synthesis. This study, based on a survey of all available literature, reviews the evolution of regional climate change and its effects in the arid and semi-arid regions of China over the last century. The present review examines three aspects of the surveyed previous studies: data, methods, and subjects, and then summarizes essential scientific findings into four subject areas: the origin and expansion of arid and semi-arid regions, the characteristics of climate change in these areas, the drivers of climate change in arid and semi-arid zones, and the consequences of climate change in such environments. Finally, six key directions for future research on climate change and its effects on the arid and semi-arid regions of China are proposed.