气象与减灾研究
氣象與減災研究
기상여감재연구
METEOROLOGY AND DISASTER REDUCTION RESEARCH
2015年
1期
25-36
,共12页
孙素琴%郑婧%许爱华%陈云辉
孫素琴%鄭婧%許愛華%陳雲輝
손소금%정청%허애화%진운휘
梅雨锋暴雨%数值模拟%超低空急流%中尺度扰动%高低空耦合
梅雨鋒暴雨%數值模擬%超低空急流%中呎度擾動%高低空耦閤
매우봉폭우%수치모의%초저공급류%중척도우동%고저공우합
Mei-yu front%numerical simulation%super-low level jet%meso-scale perturbations%coupling of lower with upper circulation
利用常规气象观测资料、高时空分辨率TBB资料以及NCEP/FNL再分析资料,对2011年6月14—15日江西省北部梅雨锋暴雨过程进行了天气分析。同时,利用中尺度数值模式WRF对此次梅雨锋暴雨过程进行数值模拟,分析暴雨的中尺度系统结构特征。结果表明:稳定的环流形势下,500 hPa低槽后部冷空气与强盛的西南暖湿气流在江南北部持续对峙,使得暴雨区稳定维持在江西省北部。低层充沛的水汽供应、强的热力不稳定及强烈的天气尺度、中尺度辐合和地形抬升是此次暴雨产生的有利环境场和触发条件。锋区及其附近的锋生过程与强降水密切相关,冷暖气流在地面至对流层中低层的交馁,激发正涡度柱沿锋区倾斜爬升,强烈的上升气流穿越锋区激发大量不稳定能量释放。超低空急流的脉动和稳定维持为暴雨发生的有利水汽输送机制,高低空水平距离的缩短有利于高低空急流的耦合、垂直运动的发展和降水强度的加强。强降水区上空β中尺度对流扰动在冷、暖气流对峙区内不断生成、发展、东移,加之局地地形等作用致使大暴雨的发生。
利用常規氣象觀測資料、高時空分辨率TBB資料以及NCEP/FNL再分析資料,對2011年6月14—15日江西省北部梅雨鋒暴雨過程進行瞭天氣分析。同時,利用中呎度數值模式WRF對此次梅雨鋒暴雨過程進行數值模擬,分析暴雨的中呎度繫統結構特徵。結果錶明:穩定的環流形勢下,500 hPa低槽後部冷空氣與彊盛的西南暖濕氣流在江南北部持續對峙,使得暴雨區穩定維持在江西省北部。低層充沛的水汽供應、彊的熱力不穩定及彊烈的天氣呎度、中呎度輻閤和地形抬升是此次暴雨產生的有利環境場和觸髮條件。鋒區及其附近的鋒生過程與彊降水密切相關,冷暖氣流在地麵至對流層中低層的交餒,激髮正渦度柱沿鋒區傾斜爬升,彊烈的上升氣流穿越鋒區激髮大量不穩定能量釋放。超低空急流的脈動和穩定維持為暴雨髮生的有利水汽輸送機製,高低空水平距離的縮短有利于高低空急流的耦閤、垂直運動的髮展和降水彊度的加彊。彊降水區上空β中呎度對流擾動在冷、暖氣流對峙區內不斷生成、髮展、東移,加之跼地地形等作用緻使大暴雨的髮生。
이용상규기상관측자료、고시공분변솔TBB자료이급NCEP/FNL재분석자료,대2011년6월14—15일강서성북부매우봉폭우과정진행료천기분석。동시,이용중척도수치모식WRF대차차매우봉폭우과정진행수치모의,분석폭우적중척도계통결구특정。결과표명:은정적배류형세하,500 hPa저조후부랭공기여강성적서남난습기류재강남북부지속대치,사득폭우구은정유지재강서성북부。저층충패적수기공응、강적열력불은정급강렬적천기척도、중척도복합화지형태승시차차폭우산생적유리배경장화촉발조건。봉구급기부근적봉생과정여강강수밀절상관,랭난기류재지면지대류층중저층적교뇌,격발정와도주연봉구경사파승,강렬적상승기류천월봉구격발대량불은정능량석방。초저공급류적맥동화은정유지위폭우발생적유이수기수송궤제,고저공수평거리적축단유리우고저공급류적우합、수직운동적발전화강수강도적가강。강강수구상공β중척도대류우동재랭、난기류대치구내불단생성、발전、동이,가지국지지형등작용치사대폭우적발생。
In this paper, the routine observational data, high resolution TBB data and NECP FNL reanalysis data were used to analyze a Meiyu front rainstorm process occurred during 14-15 June 2011, and the WRF model was used to simulate this process. The results showed that the rainstorm maintained over the northern part of Jiangxi due to the stable circulation situation and the continuous intersection between the cold air flow behind the 500 hPa trough and the strong southwest airflow. The trigger mechanism of rainstorm came from plentiful water supplement in low level, strong thermal instability, synoptic-scale and meso-scale convergences and terrain lifting. Frontal zone and its frontogenesis process were closely related to the occurrence of heavy rain. Positive vorticity developed upward along the frontal zone , which enhanced convective ascending motion and release of instable energy. Continuous southeast wind of low-level jet in the boundary layer provided the continuous water vapor. The short distance between high-low level jets was conducive to the development of vertical velocity and precipitation intensity.