Multi-factor Response and Analysis of Abnormal Climate in Zhangjiajie in August 2024

Zhu Jinju; Hu Zhenju; Liang Ke; Zhou Yaqin; Wang Shunmin; Dai Bin; Chen Nuo

doi:10.16765/j.cnki.1673-7148.2026.03.004

Abstract：This study systematically analyzes the anomalous characteristics of the extreme high tem-perature and low precipitation event in Zhangjiajie during August 2024 using multi-source meteorological observation data,NCEP reanalysis data,and ocean monitoring products,and reveals its physical mecha-nisms from the perspective of multiple factors such as atmospheric circulation,water vapor transport,and air-sea interaction.The results are as follows:(1)The Northern Hemisphere 500 hPa geopotential height field exhibited a dipole pattern,with a"two-trough-one-ridge"circulation configuration over the mid-to-high latitudes of Eurasia.The eastward propagation of split short-wave troughs from the Ural Mountains low trough,together with the anomalously strong,westward-extending,and northward-shifting Western Pacific Subtropical High(WPSH),constituted the key circulation systems responsible for this event.(2)A vertical circulation cell,characterized by low-level convergence and ascent over the eastern Si-chuan-Chongqing-western Hunan region and upper-level divergence and subsidence from the Hetao area to North China,enhanced the subsidence warming effect.(3)The vertically integrated water vapor trans-port in the troposphere exhibited a"northward convergence and southward divergence"pattern,with cen-tral China acting as a net water vapor outflow region,thereby exacerbating the drought conditions.(4)The WPSH area,intensity,ridge line,and western extension ridge point indices all showed significant anomalies,with the ridge line and western extension ridge point being significantly positively correlated with the daily maximum temperature in Zhangjiajie.(5)This event occurred during the decay year of an eastern-Pacific type El Niño,and its climatic response differed markedly from historical years of the same type,highlighting the increasing complexity of ENSO impacts under global warming.(6)Although the South China Sea summer monsoon was delayed and weaker,the Walker circulation intensified phase-wise in August,exerting a positive feedback on the high temperature and drought by strengthening the subtrop-ical high.This study elucidates the driving mechanisms of extreme events in climate-sensitive regions through multi-factor synergy,providing a scientific basis for predicting such events and informing disaster response strategies.