Record-breaking summer rainfall in the Asia–Pacific region attributed to the strongest Asian westerly jet related to aerosol reduction during COVID-19

Abstract The Asia–Pacific region suffered record rainfall in summer 2020, which was accompanied by the strongest Asian subtropical westerly jet (ASWJ) of past four decades. Meanwhile, COVID-19 pandemic spread rapidly around world, resulting an abrupt reduction emissions East Asia. Here, we investigate whether enhanced ASWJ induced plummeting aerosols contributed to record-breaking rainfall. results show that tropospheric warming Southeast Asia, particular southern China, due local aerosol reduction, acted increase meridional temperature gradients mid–lower troposphere, supported a strong upper troposphere via thermal wind balance. latter divergence over region, provided favorable ascending motion for took place there. Therefore, against background carbon neutrality (i.e. aerosols), our imply more region.