Synergistic effects of atmospheric circulation anomalies and land–atmosphere coupling on the 2022–2023 extreme drought in Southwest China

Abstract Drought ranks among the most destructive natural disasters globally. Southwest China (SWC) is one of China’s principal drought–prone regions. From winter 2022 to spring 2023, a record-breaking winter–spring drought struck SWC, with meteorological drought intensity reaching its highest level since 1961. Here, we investigated the exceptional characteristics and dominant driving factors during this extreme drought. We found that the extreme drought was predominantly driven by record‐breaking precipitation deficit, which was attributed to persistent large–scale atmospheric circulation anomalies, which weakened southerly moisture transport and strengthened subsidence over SWC. Concurrently, extreme precipitation shortages induced soil moisture (SM) deficits and elevated atmospheric vapor pressure deficit (VPD). When SM reduced below the 40th percentile, land–atmosphere coupling intensified sensible heat flux, leading to increases in surface temperature and VPD, thereby further exacerbating drought. Surface diabatic heating and increased atmospheric circulation anomalies established a positive feedback mechanism, resulting in sustaining SM deficits for months and culminating in the unprecedented drought in April–May. This study advances understanding of the physical mechanisms of drought formation and development over SWC through the synergistic effects of atmospheric circulation anomalies and land–atmosphere interaction.