干旱气象
榦旱氣象
간한기상
GANSU METEOROLOGY
2011年
3期
322-329
,共8页
冬季暴雨%南支槽%准静止锋
鼕季暴雨%南支槽%準靜止鋒
동계폭우%남지조%준정지봉
torrential rain in winter%southern branch trough%quasi-stationary front
利用气象常规观测资料、美国国家环境预报中心NCEP 1°×1°再分析资料,对贵州2010年一次冬季暴雨极端天气的诊断分析发现:这次暴雨天气主要是因南支槽、准静止锋以及850 hPa切变共同影响造成,其形成原因与贵州秋末暴雨非常近似,属于冬行秋令。对比分析本次降水过程中2个重要天气系统之一的南支槽与气候平均态的差异发现:本次过程中南支槽前的强偏南气流提供了有利的暖湿输送,不同于气候平均态的干暖输送;南支槽前偏南气流的水汽辐合、上升运动、低层辐合、高层辐散均明显强于气候平均态。另一个重要天气系统准静止锋具有2个主要特点:(1)锋区温度较高,锋面逆温层温度均高于0℃;(2)锋区表现为等θse密集区,锋区狭窄而陡峭,锋后低空逆温明显。在暴雨发生期间,静止锋是一个加强北抬的过程,在静止锋加强的过程中促使了水汽辐合、上升运动发展以及低层辐合等产生暴雨的有利条件发展。
利用氣象常規觀測資料、美國國傢環境預報中心NCEP 1°×1°再分析資料,對貴州2010年一次鼕季暴雨極耑天氣的診斷分析髮現:這次暴雨天氣主要是因南支槽、準靜止鋒以及850 hPa切變共同影響造成,其形成原因與貴州鞦末暴雨非常近似,屬于鼕行鞦令。對比分析本次降水過程中2箇重要天氣繫統之一的南支槽與氣候平均態的差異髮現:本次過程中南支槽前的彊偏南氣流提供瞭有利的暖濕輸送,不同于氣候平均態的榦暖輸送;南支槽前偏南氣流的水汽輻閤、上升運動、低層輻閤、高層輻散均明顯彊于氣候平均態。另一箇重要天氣繫統準靜止鋒具有2箇主要特點:(1)鋒區溫度較高,鋒麵逆溫層溫度均高于0℃;(2)鋒區錶現為等θse密集區,鋒區狹窄而陡峭,鋒後低空逆溫明顯。在暴雨髮生期間,靜止鋒是一箇加彊北抬的過程,在靜止鋒加彊的過程中促使瞭水汽輻閤、上升運動髮展以及低層輻閤等產生暴雨的有利條件髮展。
이용기상상규관측자료、미국국가배경예보중심NCEP 1°×1°재분석자료,대귀주2010년일차동계폭우겁단천기적진단분석발현:저차폭우천기주요시인남지조、준정지봉이급850 hPa절변공동영향조성,기형성원인여귀주추말폭우비상근사,속우동행추령。대비분석본차강수과정중2개중요천기계통지일적남지조여기후평균태적차이발현:본차과정중남지조전적강편남기류제공료유리적난습수송,불동우기후평균태적간난수송;남지조전편남기류적수기복합、상승운동、저층복합、고층복산균명현강우기후평균태。령일개중요천기계통준정지봉구유2개주요특점:(1)봉구온도교고,봉면역온층온도균고우0℃;(2)봉구표현위등θse밀집구,봉구협착이두초,봉후저공역온명현。재폭우발생기간,정지봉시일개가강북태적과정,재정지봉가강적과정중촉사료수기복합、상승운동발전이급저층복합등산생폭우적유리조건발전。
Based on routine meterological observations and NCEP reanalysis data,a torrential rain occurred in Guizhou in winter of 2010 was analyzed.The results show that the southern branch trough,quasi-stationary front and shear at the level of 850 hPa resulted in this heavy rain process,and which was nearly the same as that of those heavy rain weather events occurred in the end of autumn in Guizhou.During this weather process,the south-west airflow in front of the southern branch trough was warm and moist which was different from climate mean state(dry and warm),and the moisture convergence,rising motion and the wind convergence at lower layer but divergence at upper layer were stronger than that of the climate mean state.There were two main features of quasi-stationary front in this case: in vertical direction,the frontal inversion layer's temperature was above 0 ℃;the front zone presented the dense area of the pseudo-equivalent potential temperature,the frontal structure was narrow and sharp,and behind the frontal zone,the lower level inversion was very significant.The frontogenesis provided favorable large-scale condition for the torrential rain in winter.