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2016年陕甘宁地区一次强降水的大气环流特征及水汽输送途径

胡  皓1,2李丽平1王建鹏2马晓华2   

  1. 1.南京信息工程大学大气科学学院,江苏 南京 210044;
    2.陕西省气象台,陕西 西安 710014
  • 出版日期:2018-10-31 发布日期:2018-10-31
  • 通讯作者: 王建鹏(1972— ),男,陕西西安人,高级工程师,研究方向为天气预报. E-mail:xawjp@163.com。
  • 作者简介:胡皓(1984— ),男,陕西西安人,高级工程师,研究方向为短期天气预报. E-mail:123723129@qq.com。
  • 基金资助:

    中国气象局预报员专项项目(CMAYBY2018-074)和陕西省气象局科学技术研究项目(2017M-2)共同资助

A Case Study on the Heavy Rainfall in Shaanxi-Gansu-Ningxia and Associated Atmospheric Circulations and Water Vapor Channels in 2016

HU Hao1,2, LI Liping1, WANG Jianpeng2, MA Xiaohua2   

  1. 1. School of Atmospheric Sciences, Nanjing University of Information Science & Technology, Nanjing 210044, China;
    2. Shaanxi Provincial Meteorological Observatory, Xi’an 710014, China
  • Online:2018-10-31 Published:2018-10-31

摘要:

利用降水常规和加密观测资料以及ERA-Interim再分析资料,对2016年7月24日发生在陕甘宁地区强降雨过程的大气环流特征及水汽输送途径进行诊断分析。结果表明,在对流层高层,陕甘宁地区位于东亚西风带高空急流入口区右侧,辐散显著,通过抽吸作用激发了较强的局地垂直运动。在对流层中层,不断有低槽从低涡底部分裂出来,并携带冷空气南下。对流层低层风场上,850 hPa以下陕甘宁地区为强辐合区,冷暖空气强烈交汇,锋生条件好。此外,850~200 hPa高度,都表现为强烈上升运动。副热带高压向西深入中国大陆,呈东北—西南向分布,副高后部来自孟加拉湾的西南暖湿气流为强降水天气建立了稳定的水汽通道,而来自南海的水汽输送非常弱。

关键词: 强降雨, 水汽通道, 高空急流, 副热带高压

Abstract:

Based on the conventional observation and intensive observation of precipitation and reanalysis data of ERA-Interim, the atmospheric circulation characteristics and water vapor channels of the heavy rainfall in Shaanxi-Gansu-Ningxia on 24 July 2016 were diagnosed and studied. The results show that the divergence was obvious in Shaanxi-Gansu-Ningxia being located in the right side of entrance region of upper-level jet stream of East Asian westerlies on the upper troposphere, which induced the strong vertical motion by pumping action. On the middle troposphere, the low troughs were frequently split from the bottom of low vortex, and carried the cold air to southward. On the lower troposphere, the convergence was significant in Shaanxi-Gansu-Ningxia, and the intersection of cold and warm air flow was strong, which caused the frontogenesis potential to enhance. The subtropical high moved westward to the mainland of China and distributed from southwest to northeast. The strong ascending motion existed from 850 hPa to 200 hPa over Shaanxi Province. The strong warm and humid air flow from the Bay of Bengal being located in the rear of subtropical high was benefit for the stable formation of water vapor channels for the heavy rainfall, while the water vapor transportation from South China Sea was weak.

Key words: heavy rainfall, water vapor channels, upper-level jet stream, subtropical high

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