主办单位：中国气象局沈阳大气环境研究所
国际刊号：ISSN 1673-503X
国内刊号：CN 21-1531/P
气象与环境学报

气象与环境学报 ›› 2018, Vol. 34 ›› Issue (4): 1-10.doi: 10.3969/j.issn.1673-503X.2018.04.001

• 论文 •    下一篇

中亚低涡背景下中天山地区一次短时强降水过程中尺度特征

万瑜1,2  曹兴3  杨莲梅1,4   

  1. 1. 中国气象局乌鲁木齐沙漠气象研究所，新疆 乌鲁木齐 830002；2. 新疆气象台，新疆 乌鲁木齐 830002；3. 乌鲁木齐市气象局，新疆 乌鲁木齐 830002；4. 中亚大气科学研究中心，新疆 乌鲁木齐 830002
  • 收稿日期:2017-04-26 修回日期:2017-07-03 出版日期:2018-08-31 发布日期:2018-09-03

Mesoscale characteristics of a short-time heavy rainfall under the background of the Central Asian Vortex in the middle Tianshan of Xinjiang province

WAN Yu1,2  CAO Xing3  YANG Lian-mei1,4   

  1. 1. Tianjin Meteorological Observatory, Tianjin 300074, China; 2. Tianjin Climate Center, Tianjin 300074, China; 3. Bureau of Hydrology, Haihe Water Conservancy Commission, Tianjin 300170, China
  • Received:2017-04-26 Revised:2017-07-03 Online:2018-08-31 Published:2018-09-03

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摘要：

利用常规气象观测资料、区域自动气象站观测资料及卫星、多普勒天气雷达、风廓线等非常规探测资料和美国气象环境预报中心（National Centers for Environmental Prediction，NCEP）逐日4次的1°×1°再分析资料，对2015年6月27—28日中天山地区一次短时强降水过程的中尺度对流条件和对流系统特征进行分析，以期为中亚低涡背景下降水的中尺度诊断分析提供参考。结果表明：此次中天山地区强降水天气过程是中亚低涡前部的东北—西南向气旋式切变和深厚的西南暖湿气流共同作用引发的，低层切变和气旋式辐合的动力抬升、地面中尺度辐合线是此次强对流天气的直接触发因子。里咸海南侧的水汽沿着中亚低涡底部的偏西气流和前部的西南气流输送至强降水区，为此次短时强降水过程提供了充沛的水汽条件。大气可降水量的跃变和风廓线产品的垂直变化特征与短时强降水的开始、加强及减弱具有较好的对应关系；红外云图反映了中天山地区短时强降水发生在对流云团云顶亮温(Temperature of Black Body，TBB)梯度最大处；短时强降水由低质心和高效率的降水回波造成的，降水强度与回波顶高度存在较好的正相关关系，为今后提高短时强降水预报准确率提供了量化的指标。

关键词: 中天山, 中亚低涡, 短时强降水, 诊断, 大气可降水量, 风廓线, TBB

Abstract:

Using the data from conventional and automatic weather stations, Doppler radar, satellite and wind-profiler radar as well as the associated NCEP (National Centers for Environmental Prediction) reanalysis , we analyzed the convectie conditions and mesoscale characteristics of a short-time heavy rainfall in the middle Tianshan of Xinjiang province on June 27-28, 2015. The mesoscale diagnostic analysis under the background of the central Asian vortex was carried out to provide a reference for the forecasters. The results indicate that this strong convective weather process is caused by the interaction of the northeast to southwest anticyclonic shear in front of the central Asian vortex and the deep warm-wet flow coming from southwest. The direct impact systems to this process are convective instability, including the dynamic lifting condition, shear line in the lower troposphere, surface mesoscale convergence line and the cyclone type convergence center. The convergence of water vapor at the bottom of the central Asian vortex along west and that in front of the central Asian vortex along southwest attributes a favorable vapor condition to this process. Analysis shows that the abrupt variation of GPS-PWV (Global Position System, Precipitable water vapor) and vertical variation of  wind from wind-profiler radar have a good correspondence to the beginning, strengthening and ending of the precipitation. Satellite IR imagery shows that the short-time strong rainfall occurs at the maximum gradient area of the  brightness temperature of convective clouds and is identified by the low centroid and the high-efficiency precipitation echoes. The precipitation intensity is positively correlated with the height of echo top. This study provides a quantitative index for improving the forecast accuracy of short-time strong rainfall.

Key words: Middle Tianshan, Central Asian vortex, Short-time heavy rainfall, Mesoscale characteristics, Precipitable water vapor, Wind profile, TBB

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