Possible linkage between sudden stratospheric warmings and transboundary aerosol transport from South Asia to the Tibetan Plateau

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.