暴雨灾害
暴雨災害
폭우재해
TORRENTIAL RAIN AND DISASTERS
2012年
1期
15-22
,共8页
杜小玲%高守亭%许可%武文辉
杜小玲%高守亭%許可%武文輝
두소령%고수정%허가%무문휘
阻塞环流%冻雨%概念模型
阻塞環流%凍雨%概唸模型
조새배류%동우%개념모형
blocking pattern%freezing rain%conceptual model
利用NCEP 1×1、2.5×2.5再分析格点资料以及2000—2009年贵州省冻雨个例资料,对该省12次阻塞环流背景下强冻雨过程的天气学特征进行分析,归纳强冻雨的预报着眼点及概念模型。结果表明:1)强冻雨天气与亚洲中高纬度阻塞环流和中低纬度南支锋区密切联系,位势高度场在20—30 N之间存在4~5条等值线,564~568 dagpm线向南伸展到30 N以南;2)700 hPa上西南急流显著,最大风速达到20~24 m.s-1,其作用在于提供暖湿水汽和逆温顶部的增温效应;3)低空和地面是显著的冷垫,冻雨天气在准静止锋存在的背景下产生,准静止锋又与相对湿度大于70%以上的高湿区相联系,而影响贵州的准静止锋云系,处在锋上的具有暖湿云的特点,锋下的具有冷湿云的特点;4)强冻雨期间,对流层中低空逆温梯度加大,最大可达8~10℃以上。
利用NCEP 1×1、2.5×2.5再分析格點資料以及2000—2009年貴州省凍雨箇例資料,對該省12次阻塞環流揹景下彊凍雨過程的天氣學特徵進行分析,歸納彊凍雨的預報著眼點及概唸模型。結果錶明:1)彊凍雨天氣與亞洲中高緯度阻塞環流和中低緯度南支鋒區密切聯繫,位勢高度場在20—30 N之間存在4~5條等值線,564~568 dagpm線嚮南伸展到30 N以南;2)700 hPa上西南急流顯著,最大風速達到20~24 m.s-1,其作用在于提供暖濕水汽和逆溫頂部的增溫效應;3)低空和地麵是顯著的冷墊,凍雨天氣在準靜止鋒存在的揹景下產生,準靜止鋒又與相對濕度大于70%以上的高濕區相聯繫,而影響貴州的準靜止鋒雲繫,處在鋒上的具有暖濕雲的特點,鋒下的具有冷濕雲的特點;4)彊凍雨期間,對流層中低空逆溫梯度加大,最大可達8~10℃以上。
이용NCEP 1×1、2.5×2.5재분석격점자료이급2000—2009년귀주성동우개례자료,대해성12차조새배류배경하강동우과정적천기학특정진행분석,귀납강동우적예보착안점급개념모형。결과표명:1)강동우천기여아주중고위도조새배류화중저위도남지봉구밀절련계,위세고도장재20—30 N지간존재4~5조등치선,564~568 dagpm선향남신전도30 N이남;2)700 hPa상서남급류현저,최대풍속체도20~24 m.s-1,기작용재우제공난습수기화역온정부적증온효응;3)저공화지면시현저적랭점,동우천기재준정지봉존재적배경하산생,준정지봉우여상대습도대우70%이상적고습구상련계,이영향귀주적준정지봉운계,처재봉상적구유난습운적특점,봉하적구유랭습운적특점;4)강동우기간,대류층중저공역온제도가대,최대가체8~10℃이상。
By using NCEP global 1°×1° re-analysis data and 2.5°×2.5°mean re-analysis data,an analysis is made on 12 severe freezing rain events with blocking pattern in Guizhou.The results are as follows.(1) The severe freezing rain is relates to blocking circulation in mid-high latitude over Asia and Europe.Frontal zone in low latitude is favorable for establishment and maintenance of low-level southwest jet offering vapor for freezing rain occurrence and development.The cold air is strong and sustained on the ground.(2) The southwest jet is significant at 700 hPa,which provides warm moist vapor and makes the warming effect strong at the top of the temperature inversion.(3) A cold flow covers minimum altitude and the ground.The freezing rain occurs against the background of a quasi-stationary front which is related to high humidity area with the relative humidity higher than 70%.The quasi-stationary frontal cloud system in Guizhou is characterized by warm-humid cloud on the front and could-humid cloud under the front.(4) In the period of severe freezing rain,the gradient value of inversion in the lower and middle troposphere increases,and maximum gradient value is over 8-10 ℃.