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投稿时间:2010-07-27 修订日期:2011-04-06
投稿时间:2010-07-27 修订日期:2011-04-06
中文摘要: 利用常规和非常规气象观测资料,针对2009年汛期山西境内出现的5次横切变区域性暴雨天气过程进行流型配置、物理量诊断、卫星、雷达、GPS/MET资料以及可预报性综合分析。发现:5次横切变暴雨过程中2009年7月7—8日的暴雨过程是暴雨范围最大、降水强度最强、系统配置最完整的一次;连阴雨过程中无论是暴雨日还是非暴雨日都具有湿度大、湿层厚的特征,这是与其他4次非连阴雨暴雨过程的最大区别;对流性或混合性暴雨,在暴雨发生前12小时500 hPa及其以下都具有θse随高度的增高而减小、500 hPa以上都具有θse随高度的增高而增加的特征,稳定性暴雨则具有θse随高度的增高而增加的特征。 5次暴雨过程500 hPa副高均为纬向型,700 hPa均有西南急流轴配合以及大陆小高压相伴,暴雨落区均位于气柱水汽总量梯度的大值区到大值区南(东)部0.5个经纬度的范围内。分析结果表明:小高压的位置不同导致了不同风向的辐合和不同走向的横切变线产生,急流头向北伸展的纬度不同导致了横切变线所处的纬度差异,直接影响暴雨的落区;低涡的强度不同使得降水量发生明显的差异;高低空系统配置越完整暴雨落区和量级的可预报性也越强;连阴雨过程中垂直速度、水汽通量散度、垂直风切变是提前24小时判断暴雨发生与否的敏感因子;水汽锋区走向与中低层切变线走向基本一致,在降水开始前,稳定性暴雨过程比强对流暴雨过程水汽锋区形成时间有更多的提前量,且对流越强烈水汽锋区形成的时间越晚。
中文关键词: 横切变, 暴雨, 流型配置, 对比分析
Abstract:With conventional and unconventional meteorological observational data, aiming at the 5 transverse shear regional rainstorm weather processes appearing in the flood season during 2009 in Shanxi area, the authors configured the flow pattern, diagnosed the physical variables, and comprehensively analyzed the satellite, radar, and the GPS/MET data and the predictability, and discovered that within the 5 transverse shear rainstorm processes, the rainstorm process appearing during July 7-8, 2009, was the one that the range was the widest, the precipitation strength was the strongest, and the system configuration was the most complete; in the continuous rainy process, whether rainstorm days or non storm days, all have the following features that humidity was high and thick, and this was the biggest difference from the other 4 non continuous rainy rainstorm processes; the convective or mixed rainstorm, has characteristics that it would decrease with the increasing height under 500 hPa, and would increase with the increasing height above 500 hPa 12 h ahead of the rainstorm setting in. Moreover the stable rainstorm has characteristics that it would increase with the increasing height. The 500 hPa horse latitude highs were all zonal types in the 5 rainstorm processes, and the 700 hPa horse latitude highs all had the southwest axis of jet stream being combined and the continental small high being accompanied, the rainstorm falling areas were all located at the area between the big value zone of the air column total vapor gradient and its southern (eastern), within 0.5°E (N). The analysis result shows that: the location difference of the small high led to the convergence of the different wind direction and the generation of transverse shear line in different trend, the latitude difference of the jet stream head stretching toward north led to the latitude difference of transverse shear line location, which would directly influence the falling areas of rainstorms; the strength difference of low vortex made the evident difference of precipitation; the more complete the high low air system configuration is, the stronger will be the predictability of rainstorm falling area and magnitude; during the continuous rainy processes, the vertical speed, moisture flux divergence, and vertical wind shear are the sensitive factors in judging whether rainstorm will approach or not 24 h in advance. The vapor front area trend is almost consistent with the mid low layer shear line; before the rain approaches, the stable rainstorm process has more initial lead time in relation to the formation of the vapor front area than the severe convective rainstorm process, moreover, the stronger the convection is, the later the vapor front area forms.
文章编号: 中图分类号: 文献标志码:
基金项目:山西省科技攻关项目(20090311083)、中国气象局气象关键技术集成与应用项目(CMAGJ2011M11)、公益性行业(气象)科研专项(GYHY200906011)和中国气象局预报员专项(CMAYBY2011 004)等共同资助
作者 | 单位 |
苗爱梅 | 山西省气象台,太原 030006 |
贾利冬 | 山西省气象局,太原 030002 |
李苗 | 山西省气象科技服务中心,太原 030002 |
晋立军 | 山西省人工降雨防雹办公室,太原 030032 |
范光海 | 山西省气象局培训中心,太原 030032 |
引用文本:
苗爱梅,贾利冬,李苗,晋立军,范光海,2011.2009年山西5次横切变暴雨的对比分析[J].气象,37(8):956-967.
MIAO Aimei,JIA Lidong,LI Miao,JIN Lijun,FAN Guanghai,2011.Comparative Analysis of Five Transverse Shear Rainstorms During the Year 2009 in Shanxi[J].Meteor Mon,37(8):956-967.
苗爱梅,贾利冬,李苗,晋立军,范光海,2011.2009年山西5次横切变暴雨的对比分析[J].气象,37(8):956-967.
MIAO Aimei,JIA Lidong,LI Miao,JIN Lijun,FAN Guanghai,2011.Comparative Analysis of Five Transverse Shear Rainstorms During the Year 2009 in Shanxi[J].Meteor Mon,37(8):956-967.