干旱气象 ›› 2026, Vol. 44 ›› Issue (3): 437-450.DOI: 10.11755/j.issn.1006-7639-2026-03-0437

• 论文 • 上一篇    下一篇

秦岭及周边地区夏季极端降水环流特征及成因分析

井宇1,2(), 陈闯2,3, 赵强1,2, 李明1,2, 何娟1,2   

  1. 1 陕西省气象台陕西 西安 710014
    2 中国气象局秦岭和黄土高原生态环境气象重点开放实验室陕西 西安 710016
    3 陕西省气象科学研究所陕西 西安 710016
  • 收稿日期:2026-03-11 修回日期:2026-05-11 出版日期:2026-06-30 发布日期:2026-07-16
  • 作者简介:井宇(1985—),女,高级工程师,主要从事短临天气预报技术研究。E-mail: jingyu.1128@163.com
  • 基金资助:
    中国气象局秦岭和黄土高原生态环境气象重点开放实验室开放研究基金课题(2025G-10);中国气象局复盘总结专项(FPZJ2025-131);陕西省自然科学基础研究计划项目(2025JC-YBMS-284)

Circulation characteristics and causal analysis of extreme summer precipitation over the Qinling Mountains and surrounding regions

JING Yu1,2(), CHEN Chuang2,3, ZHAO Qiang1,2, LI Ming1,2, HE Juan1,2   

  1. 1 Shaanxi Meteorological ObservatoryXi’an 710014, China
    2 CMA Key Laboratory of Eco-Environment and Meteorology for the Qinling Mountains and Loess PlateauXi’an 710016, China
    3 Shaanxi Institute of Meteorological SciencesXi’an 710016, China
  • Received:2026-03-11 Revised:2026-05-11 Online:2026-06-30 Published:2026-07-16

摘要:

为深入认识秦岭及周边地区夏季极端降水的环流特征和形成机制,本文基于2008—2025年地面气象站降水数据和欧洲中期天气预报中心ERA5再分析资料,应用谱聚类方法,将秦岭北部和南部(以34°N为界划分)的区域小时极端降水(Regional Hourly Extreme Precipitation,RHEP)分别归纳为3类和4类典型环流型,探讨夏季RHEP的主要环流特征及水汽、热力和动力条件。结果表明:1)各类环流型200 hPa均受南亚高压边缘附近辐散场影响,500 hPa及以下多表现为西太平洋副高控制下的暖湿气流输送与短波槽、切变线等共同作用;副高外围气流向秦岭及周边输送充沛水汽,并在极端降水区形成明显辐合;不同环流配置及其与复杂地形的抬升辐合效应共同强化垂直运动,是导致RHEP高发区空间分布不同的重要原因。2)各类环流型对流层低层副高外围表现为西南、偏南或东南风异常,部分类型伴随青藏高原东北侧偏北风异常,有利于冷暖气流交汇,从而促进RHEP发生。3)水汽诊断分析表明,阿拉伯海、孟加拉湾、南海、西太平洋以及东海等多源水汽在华南及华东汇合后向秦岭及周边地区输送;秦岭北部和南部区域各环流型以对流层中低层南边界水汽输入为主,部分类型还受东边界水汽输入影响。4)各类环流型RHEP频次最大值均位于特殊地形附近,普遍具有较低对流抑制能量(Convective Inhibition,CIN)和较大的K指数,表明大气不稳定明显,较弱的抬升机制即可触发对流发展。

关键词: 秦岭及周边地区, 极端降水, 环流特征, 特殊地形

Abstract:

To further understand the circulation characteristics and formation mechanisms of summer extreme precipitation over the Qinling Mountains and surrounding areas, this study used precipitation data from automatic weather stations and ERA5 reanalysis data from the European Centre for Medium-Range Weather Forecasts from 2008 to 2025. Using spectral clustering method, the regional hourly extreme precipitation (RHEP) in the north and south of the Qinling Mountains (divided along 34°N) was classified into three and four typical circulation patterns, respectively. The dominant circulation features, water vapor, thermal, and dynamic conditions of summer RHEP were further investigated. The results are as follows: (1) At 200 hPa, all circulation types are influenced by divergence near the periphery of the South Asian High; at 500 hPa and below, these patterns are predominantly characterized by the combined effects of warm, moist air transport associated with the Western Pacific Subtropical High and short-wave troughs, shear lines, and similar features. Abundant moisture is transported by the peripheral airflow of the Subtropical High toward the Qinling Mountains and surrounding regions, producing pronounced convergence over regions of extreme precipitation. The combined effects of different circulation configurations and their interactions with complex terrain through orographic lifting and convergence intensify vertical motion, which is a key factor contributing to the spatial variability of RHEP occurrence. (2) In the lower troposphere, the periphery of the Subtropical High in each circulation pattern is characterized by anomalous southwesterly, southerly, or southeasterly airflow, with some types accompanied by anomalous northerly airflow on the northeastern side of the Qinghai-Xizang Plateau, favoring the confluence of cold and warm air and thereby promoting the occurrence of RHEP. (3) Water vapor diagnostic analysis reveals that multi-source water vapor from the Arabian Sea, Bay of Bengal, South China Sea, Western Pacific Ocean, and East China Sea converges over South China and East China, and is subsequently transported to the Qinling Mountains and its adjacent areas. In the areas north and south of the Qinling Mountains, most circulation patterns are predominantly influenced by water vapor input from the southern boundary of the lower-to-middle troposphere, while certain circulation types are predominantly influenced by water vapor input from the eastern boundary. (4) The peak frequency of RHEP for each circulation type occurs near specific topographic features, generally characterized by low convective inhibition (CIN) and high K-index values, indicating pronounced atmospheric instability, where even weak lifting mechanisms are sufficient to trigger the development of convection.

Key words: the Qinling Mountains and surrounding regions, extreme precipitation, circulation characteristics, special topography

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