ANALYSIS OF MULTI-SCALE CHARACTERISTICS OF A JULY 2015 PERSISTENTLY LONG HEAVY RAINFALL IN GUANGXI
-
摘要: 利用多源气象资料，通过综合诊断分析方法，对2015年一次广西持续性暴雨过程进行多尺度特征分析。(1) 南亚高压经历了双体型构建，副热带长波槽有利于冷空气南下和高空急流的建立。El Niño状态下，副高强度偏强，位置偏西、偏南，有利于暖湿气流向广西输送。南亚高压过渡层与副高对峙，有利于冷暖空气在广西交汇。(2) 影响天气系统有高空槽、切变线、冷锋、低空急流、季风槽及低涡等多天气系统。降雨分为锋前暖区、锋面、高空槽加强、季风槽与低涡等四个阶段。(3) 中尺度特征为锋前暴雨发生在MCC云团形成到减弱期，雷达强回波呈弓型，对流性强；锋面暴雨发生在MCC减弱后云带，雷达强回波为弓型向直线型转换，对流性减弱；高空槽加强暴雨为直线型云系和雷达回波增强；季风槽与低涡暴雨为增强的涡旋型云系和雷达强回波。(4) 暴雨发生在总体地势为云贵高原下坡和地面喇叭口地形辐合的桂西北、海陆分布差异的沿海及山脉迎风坡的桂东南。可见，长时间持续性暴雨过程是一个多尺度和多天气系统相互作用的结果，暴雨发生在有利的大尺度环流背景和天气系统配置下的中小尺度系统频繁发生处，地形助推暴雨作用明显。深刻理解持续性暴雨发生的尺度特征可提高该类天气预报能力。Abstract: Based on multi-source data, the multi-scale feature of an persistently long heavy rainfall processin Guangxi in July 2015 is analyzed through comprehensive diagnosis and analysis, and the results are shown as follows: (1) A South Asia high experienced an establishment that featured twin bodies, and a subtropical long wave trough was conducive to the southward advancement of cold air and establishment of a southwest jet stream. In the El Niño state, a West Pacific subtropical high was stronger and its position was more to the west and south as compared with the normal, favoring the transportation of warm and moist air flow to Guangxi. The transition layer of the South Asia high steadily confronted with the subtropical high, favorable for the intersection in Guangxi of cold and wet air; (2) The influence systems of this process were an upper trough, a shear line, a cold front, a low-level jet, a monsoon trough and a low vortex. The heavy rain process went through four stages: a warm sector ahead of a front, frontal surface, the strengthening of an upper-level trough and a monsoon trough and a vortex; (3) For the type of being ahead of a front, the rainstorm happened from the formation to the weakening of MCC, the radar echo was of a bow-type, and the convection was strong; For the front type, the rainstorm happened in the cloud band after the MCC weakened, the radar echo changed from a bow-type to linear, and the convection was weakening. For the type of a strengthening upper-level trough, the rainstorm was caused by a linear cloud system, and the radar echo was enhancing. For the type of monsoon trough and vortex, the rainstorm was caused by a vortex cloud system, and the radar echo was strong; (4) Heavy rainfall occurred at the leeside of Yunnan-Guizhou Plateau, in the northwest of Guangxi with trumpet shaped topographic convergence, on the coast with the land-sea distribution difference and in southeast of Guangxi with a windward slope of mountains. Thus it could be seen that this long duration rainstorm process was caused by the interaction of multi-scale weather systems, heavy rainfall happened where there was favorable large scale circulation and frequent meso-small scale systems, and the terrain was obviously conductive to the increase of rainfall. Through deep understanding of the scale characteristics of the continuous rainstorm, the ability of forecast for the this kind of weather can be improved.
-
图 2 2015年7月南亚高压双体型构建过程中200 hPa高度场
a. 19日20时；b. 22日20时；c. 24日20时；d. 31日20时。“▲”标注为广西。单位：dagpm。
图 10 7月FY2F气象卫星TBB演变特征
a. 22日20时30分；b. 23日04时30分；c. 23日08时30分；d. 23日12时30分；e. 24日02时30分；f. 26日20时30分。
图 11 7月地面中尺度自动站观测风场及辐合线或涡旋环流
a. 22日20时；b. 23日04时；c. 23日08时；d. 23日12时；e. 24日02时；f. 26日20时。
-
[1] 鲍名.近50年我国持续性暴雨的统计分析及其大尺度环流背景[J].大气科学, 2007, 31(5):779-792. [2] 雷雨顺.经向型持续性特大暴雨的合成分析[J].气象学报, 1981, 39(2):168-181. [3] 江吉喜, 范梅珠, 吴晓.我国南方持续性暴雨成因的TBB场分析[J].气象, 1998, 24(11):26-31. [4] 祁秀香, 郑永光, 伍志方, 等.一次导致大暴雨的中尺度对流系统演变和风场垂直结构特征[J].热带气象学报, 2015, 31(3): 345-354. [5] 胡亮, 何金海, 高守亭.华南持续性暴雨的大尺度降水条件分析[J].南京气象学院学报, 2007, 30(3):345-351. [6] 柳艳菊, 丁一汇, 张颖娴, 等.季风暖湿输送带与北方冷空气对"7.21"暴雨的作用[J].热带气象学报, 2015, 31(6): 721-732. [7] 何编, 孙照渤."0806"华南持续性暴雨诊断分析与数值模拟[J].气象科学, 2010, 30(2):164-171. [8] 林爱兰, 梁建茵, 李春晖, 等."0506"华南持续性暴雨的季风环流背景[J].水科学进展, 2007, 18(3):424-432. [9] 谢炯光, 纪忠萍, 谷德军, 等.广东省前汛期连续暴雨的气候背景及中期环流特征[J].应用气象学报, 2006, 17(3):354-362. [10] 陈红专, 叶成志, 杨云芸, 等.湘西北一次大暴雨过程中尺度结构特征分析[J].热带气象学报, 2015, 31(6): 839-851. [11] 黄忠, 吴乃庚, 冯业荣, 等.2007年6月粤东持续性暴雨的成因分析[J].气象, 2008, 34(4):53-60. [12] 张庆云, 陶诗言, 张顺利.1998年嫩江、松花江流域持续性暴雨的环流条件[J].大气科学, 2001, 25(4):567-576. [13] 陈添宇, 陈乾, 付双喜, 等.西北地区东部一次持续性暴雨的成因分析[J].气象科学, 2009, 29(1):115-120. [14] 李英, 张腾飞, 郭荣芬.云南一次持续性暴雨过程的非地转湿Q矢量分析[J].南京气象学院学报, 2002, 25(2):259-264. [15] 宗志平, 张小玲.2004年9月2—6日川渝持续性暴雨过程初步分析[J].气象, 2005, 31(5):37-41. [16] 陈业国, 农孟松.2008年6月广西持续性暴雨的诊断与数值模拟[J].气象科学, 2010, 30(2):250-255. [17] 林爱兰, 谷德军, 郑彬, 等. 6月广东持续性暴雨过程概念模型的建立[J].热带气象学报, 2015, 31(3): 289-299. [18] 刘国忠, 黄开刚, 罗建英, 等.基于概念模型及配料法的持续性暴雨短期预报技术探究[J].气象, 2013, 39(1):20-27. [19] 杨春, 谌芸, 方之芳, 等."07.6"广西柳州极端暴雨过程的多尺度特征分析[J].气象, 2009, 35(6):54-62. [20] 朱乾根, 林锦瑞, 寿绍文, 等.天气学原理和方法(第4版)[M].北京:气象出版社, 2007:485-492. [21] 陈见, 梁维亮, 高安宁, 等.华南季风槽暴雨特征分析[J].热带气象学报, 2015, 31(4): 536-548. -
下载:
点击查看大图
图(13)
计量
- 文章访问数: 1024
- HTML全文浏览量: 91
- PDF下载量: 503
- 被引次数: 0
粤公网安备 4401069904700003号