摘要: |
利用ECMWF高分辨率0.25×0.25格点资料、逐小时加密雨量观测资料,基于Barnes滤波原理,设计了三套从格点资料中提取中α尺度气象信息的方案,对2017年4月8日湖南的一次暖区暴雨过程进行Barnes滤波对比客观分析。结果表明:此次强降水过程发生在高空槽南侧的西南暖湿气流中,中尺度扰动是造成此次暖区暴雨的重要原因;通过选取不同参数的Barnes带通滤波方案,能够有效分离出中α尺度天气系统,进而剖析其一致性和差异特征,对中尺度雨团落区预报有很好的指示作用,同时,也可以作为判断滤波过程中产生虚假系统的参考依据,在实际业务应用中意义重大。 |
关键词: 暖区暴雨;Barnes带通滤波;中尺度辐合系统;客观分析 |
DOI: |
投稿时间:2017-08-15修订日期:2018-02-02 |
基金项目:湖南省气象局课题“ECMWF细网格和T639细网格数值预报产品的解释应用研究(XQKJ16B106)”和中国气象局预报员专项“2016年湖南极端强降雨过程多尺度特征分析(CMAYBY2017-050)”共同资助 |
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Objective Analysis of a warm zone Rainstorm in Hunan Province by Barnes Filtering |
CAI Haichao,LIU Hongwu,DENG Mei,WANG Ping |
(Loudi Meteorological Bureau of Hunan Province;Meteorological Observatory of Hunan Province) |
Abstract: |
Based on the Barnes filter theory, three sets of α mesoscale weather forecasting information from grid data were designed by using ECMWF high-resolution 0.25 × 0.25 grid data and hourly rainfall observation data, a comprehensive analysis of Barnes filter of a warm zone rainstorm in Hunan Province on April 8, 2017 was made. The results show that the heavy rainfall process took place in the southwest warm-humid flow south of the upper trough, and the mesoscale disturbance was the important reason. By selecting the Barnes band-pass filter with different parameters, it can effectively separate α-scale weather system, and then analyze the consistency and differences between them, which is a good indicator of prediction of mesoscale rain group area, otherwise, which also can be used as a reference to determine the false system generated during the filtering process, all these are significant in practical applications. |
Key words: warm zone rainstorm; Barnes band-pass filter; the mesoscale convergence system; objective analysis |