青海东部区域性短时强降水特征及其水汽来源OA
Characteristics of regional short-duration heavy rainfall in eastern Qinghai and analysis of moisture sources
青海东部地处青藏高原向黄土高原过渡地带,区域性短时强降水是该区暖季重要致灾天气之一,但其水汽来源及各源区相对贡献仍缺乏系统认识.基于2005-2025年暖季(5-9月)青海省自动气象站逐时降水观测与NCEP/FNL再分析资料,筛选出18次区域性短时强降水事件,利用FLEXPARTv11拉格朗日粒子扩散模式结合蒸发-降水(E-P)诊断技术,系统解析了该类事件的时空演变规律、水汽传输路径及各源区定量贡献.结果表明:此类事件8月最为活跃,2022-2025年频次显著增加;空间极值中心位于河湟谷地,"喇叭口"收束地形有利于水汽辐合与抬升,小时雨强峰值突破70 mm;合成环流场呈"槽前脊后"配置,低层比湿超过7 g∙kg-1,目标区域受副高外围暖湿气流与高层强辐散协同驱动;后向轨迹揭示两支主要通道:经中亚及西亚的高层干冷气流,以及源自南海、孟加拉湾及高原本地的低层暖湿气流;E-P定量诊断表明,南海北部是最关键的水汽源区,印度半岛-中南半岛及西南地区次之,高原局地、华南沿海及西太平洋亦提供显著份额.低纬海洋远距离输送与高原局地水循环的耦合效应,形成该类事件的核心水汽机制.研究结果可为青海东部短时强降水的监测预警和预报分析提供参考.
Eastern Qinghai,situated in the transitional zone between the Tibetan and the Loess Plateaus,frequent-ly experiences regional short-duration heavy rainfall(SDHR)during the warm season,yet the moisture sources and quantitative contributions from different regions are not well understood.Based on hourly precipitation obser-vations from automatic weather stations in Qinghai Province from 2005 to 2025 and NCEP/FNL reanalysis data,18 representative regional SDHR events were identified.Using the FLEXPART v11 Lagrangian particle disper-sion model combined with evaporation-precipitation(E-P)diagnostics,we analyzed the spatiotemporal evolu-tion,water vapor transport pathways,and quantitative source contributions of these events.The results reveal the following.Regional SDHR events peak in August,and their frequency markedly increased from 2022 to 2025.The spatial extreme center is located in the Hehuang Valley,where the funnel-shaped topographic configuration promotes moisture convergence and orographic lifting,with peak hourly rainfall intensities exceeding 70 mm.The composite circulation exhibits a pretrough,postridge configuration,with low-level specific humidity exceed-ing 7 g·kg-1,jointly driven by warm-moist flow along the subtropical high periphery and strong upper-level diver-gence.Lagrangian backward trajectories reveal two principal transport corridors:an upper-level dry-cold path-way via Central and West Asia,and a low-level warm-moist pathway from the South China Sea,Bay of Bengal,and local plateaus.E-P quantitative diagnostics demonstrate that the north of the South China Sea is the domi-nant moisture source,followed by the Indian Peninsula-Indochina Peninsula and southwestern China,with the lo-cal Tibetan Plateau,South China coastal regions,and western Pacific also providing significant contributions.The coupling between long-distance oceanic moisture transport and local plateau water recycling constitutes the fundamental moisture mechanism driving regional SDHR in eastern Qinghai.These findings provide a scientific reference for monitoring,early warning,and forecasting of regional SDHR in eastern Qinghai.
祁万鹏;尤桑杰;姚素香;甄国赟;巨海晨;朱玉军
青海省气象台,青海 西宁 810001青海省气象台,青海 西宁 810001南京信息工程大学气候系统预测与变化应对全国重点实验室,气象灾害教育部重点实验室,气象灾害预报预警与评估协同创新中心,江苏 南京 210044||南京信息工程大学大气科学学院,江苏 南京 210044青海省气象台,青海 西宁 810001青海省气象台,青海 西宁 810001青海省气象台,青海 西宁 810001
青海东部短时强降水水汽来源FLEXPART地形
eastern Qinghaishort-duration heavy rainfallmoisture sourcesFLEXPARTtopography
《干旱区研究》 2026 (10)
2113-2126,14
青海省气象局重点创新团队项目(QXTD2026-1)
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