Teleconnection between Atmospheric Circulation and Meteorological Drought in Southwest China

Abstract

Meteorological drought represents one of the most prevalent and consequential climate disasters in China, exerting severe impacts on regional ecosystems and socioeconomic development. This study investigates the teleconnection between meteorological drought and atmospheric circulation patterns in Southwest China from 1960 to 2022. Employing the Standardized Precipitation Evapotranspiration Index (SPEI) across multiple temporal scales alongside atmospheric circulation data, we conducted a comprehensive analysis using statistical methodologies including run theory, Mann-Kendall trend tests, and Pearson correlation analysis. These approaches enabled an in-depth examination of the spatiotemporal characteristics of drought events and their atmospheric teleconnections in the region. The results demonstrate that (1) Since 1960, the seasonal drought occurrence probability in Southwest China follows the order: spring > winter > autumn > summer. Light and moderate droughts are the predominant types in the study area, while severe droughts occur relatively infrequently, with no extreme drought events recorded. (2) Significant spatial variations in meteorological drought exist at seasonal scales across Southwest China. Spring drought generally shows a mitigation trend, summer exhibits a northeast-wet/southwest-dry pattern, autumn demonstrates increasing aridity in most regions, and winter displays a distinct southeast-wet/ central-dry/ northwest-wet gradient. (3) Regional atmospheric circulation influences exhibit distinct patterns: ENSO demonstrates the most pronounced teleconnection impact across the entire region; PDO shows strong secondary influence, particularly in southeastern and northern areas; AO exhibits relatively weak effects, mainly affecting northern and northwestern sectors; and NAO displays minimal impact, with only 7.1% of southern and northern areas showing significant positive correlations. These findings provide valuable scientific references for drought research and integrated management in Southwest China, offering both theoretical foundations and empirical support for regional economic development planning. The results contribute to enhanced drought monitoring systems and informed policymaking for climate adaptation strategies in the region.