The Relationship Between Springtime Surface Sensible Heat Enhancement over the Qinghai-Xizang Plateau and Spring Rainfall in Southern China

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  • 1. State Key Laboratory of Climate System Prediction and Risk Management/Key Laboratory of Meteorological Disaster
    Ministry of Education/Collaborative Innovation Center on Forecast and Evaluation of Meteorological DisastersNanjing University of Information Science and TechnologyNanjing 210044Jiangsu China
    2. School of Atmospheric SciencesNanjing University of Information Science and TechnologyNanjing 210044Jiangsu China

Online published: 2025-06-04

Abstract

Based on daily surface sensible heat fluxSHdata from 73 meteorological stations across the centraleastern Qinghai-Xizang Plateaudaily precipitation data from 402 stations in southern Chinaand ERA5 reanalysis datathis study investigates the springtime enhancement characteristics of SH over the central-eastern Qinghai-Xizang Plateauits influence on spring rainfall in southern Chinaand the associated physical mechanisms. The results indicate that:(1The springtime surface sensible heat peak timeTand enhancement intensityQover the central-eastern Qinghai-Xizang Plateau exhibit significant interannual and decadal variabilitywith a strong positive correlation between them. Specificallya later occurrence of the peak sensible heat in spring is as‐ sociated with a stronger enhancement intensity.2Both T and Q exhibit significant positive correlations with spring rainfall in southern China. To evaluate their combined effectsa composite index termed the Surface Sensible Heat Enhancement IndexISHis introduced. This index demonstrates a strong positive correlation with spring rainfall in southern Chinacorrelation coefficient = 0. 60p<0. 01. Moreoverits influence is largely in‐ dependent of external factorssuch as sea surface temperatures in the central-eastern Pacific and the tropical Indi‐ an Ocean.3In years with a highlowISH indexthe springtime subtropical westerly jet is anomalously south‐ wardstronger),and the westerly winds south of the Qinghai-Xizang Plateau are anomalously strongweak. The average geopotential height at 500 hPa and 850 hPa over the Chinese mainland is anomalously lowerhigh‐ er),and the lower troposphere in southern regions is dominated by an anomalously lowhighpressure system. In eastern coastal areasthe low-altitude southwestnortheastwind is anomalously strongerleading to water vapor convergencedivergence. Combined with warmcoldadvection and strong ascendingdescendingmo‐ tionthis creates conditions that are conducivenot conduciveto precipitation formation. Consequentlyspring rainfall in southern China becomes anomalously abundantscarce. This study provides new insights into the fac‐ tors contributing to spring rainfall variability in southern Chinaimproves the predictability of regional spring weather and climateand provides a robust scientific foundation for mitigating disaster risks associated with ab‐ normal spring rainfall patterns.

Cite this article

LU Yuxia, WANG Hui, CHEN Yu, LI Shuangxing, WANG Zitao, LI Dongliang . The Relationship Between Springtime Surface Sensible Heat Enhancement over the Qinghai-Xizang Plateau and Spring Rainfall in Southern China[J]. Plateau Meteorology, 0 : 1 . DOI: 10.7522/j.issn.1000-0534.2025.00066

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