干旱气象
榦旱氣象
간한기상
GANSU METEOROLOGY
2014年
5期
837-844
,共8页
李典%夏传栋%肖光梁%鲁杨%孟鹏%柴晓玲%孙彬
李典%夏傳棟%肖光樑%魯楊%孟鵬%柴曉玲%孫彬
리전%하전동%초광량%로양%맹붕%시효령%손빈
强降水%水汽输送%水汽收支
彊降水%水汽輸送%水汽收支
강강수%수기수송%수기수지
heavy Rain%transformation of water vapor%moisture budget
利用Micaps实况资料、东北区域中尺度数值模式分析场资料和常规观测资料,对2013年8月16日沈阳城区暴雨的水汽条件进行了分析。结果表明:850 hPa以下城区上空水汽含量占整层的80%以上,地面比湿呈现快速增加后减少的变化,比湿峰值对应的并不是强降水的最强时刻。强降水发生前,城区地面周围的湿度分布不均匀,水汽输送主要以南北向为主。比湿的迅速增加主要是由于降水前风向和风速的快速变化,其中主要是南风分量的贡献。城区上空垂直方向上水汽主要是850 hPa向上输送,850 hPa以下输送强度逐渐减弱。伴随着强降水的开始,水汽的垂直输送转为高度层越低,输送强度越大。强降水发生时,地面U、V方向上水汽通量快速减小。强降水发生后,地面和高空水汽输送均发生了变化。大气可降水量与降水量之间具有一定的对应关系,可降水量的大小主要是取决于水平水汽通量辐合的大小,水汽局地变化对可降水量的贡献较小。水汽通量的辐合、辐散的大小主要取决于水平风场引起的辐合、辐散的大小。
利用Micaps實況資料、東北區域中呎度數值模式分析場資料和常規觀測資料,對2013年8月16日瀋暘城區暴雨的水汽條件進行瞭分析。結果錶明:850 hPa以下城區上空水汽含量佔整層的80%以上,地麵比濕呈現快速增加後減少的變化,比濕峰值對應的併不是彊降水的最彊時刻。彊降水髮生前,城區地麵週圍的濕度分佈不均勻,水汽輸送主要以南北嚮為主。比濕的迅速增加主要是由于降水前風嚮和風速的快速變化,其中主要是南風分量的貢獻。城區上空垂直方嚮上水汽主要是850 hPa嚮上輸送,850 hPa以下輸送彊度逐漸減弱。伴隨著彊降水的開始,水汽的垂直輸送轉為高度層越低,輸送彊度越大。彊降水髮生時,地麵U、V方嚮上水汽通量快速減小。彊降水髮生後,地麵和高空水汽輸送均髮生瞭變化。大氣可降水量與降水量之間具有一定的對應關繫,可降水量的大小主要是取決于水平水汽通量輻閤的大小,水汽跼地變化對可降水量的貢獻較小。水汽通量的輻閤、輻散的大小主要取決于水平風場引起的輻閤、輻散的大小。
이용Micaps실황자료、동북구역중척도수치모식분석장자료화상규관측자료,대2013년8월16일침양성구폭우적수기조건진행료분석。결과표명:850 hPa이하성구상공수기함량점정층적80%이상,지면비습정현쾌속증가후감소적변화,비습봉치대응적병불시강강수적최강시각。강강수발생전,성구지면주위적습도분포불균균,수기수송주요이남북향위주。비습적신속증가주요시유우강수전풍향화풍속적쾌속변화,기중주요시남풍분량적공헌。성구상공수직방향상수기주요시850 hPa향상수송,850 hPa이하수송강도축점감약。반수착강강수적개시,수기적수직수송전위고도층월저,수송강도월대。강강수발생시,지면U、V방향상수기통량쾌속감소。강강수발생후,지면화고공수기수송균발생료변화。대기가강수량여강수량지간구유일정적대응관계,가강수량적대소주요시취결우수평수기통량복합적대소,수기국지변화대가강수량적공헌교소。수기통량적복합、복산적대소주요취결우수평풍장인기적복합、복산적대소。
The water vapor condition of a short-time heavy rainstorm in Shenyang on 16 August 2013 was analyzed in detail by using the Micaps data,the analytic fields of mesoscale numerical mode data,conventional observation data and automatic meteorological ob-serving data.The results indicated that water vapor content below 850 hPa accounted for more than 80%of the whole layer water vapor content.The change of ground specific humidity in rainstorm area presented increasing fast firstly and then decreasing.The maximum of specific humidity was not corresponding to the strongest moment of the heavy rain.Before the heavy rain occurrence,the distribution of humidity on surface was uneven in Shenyang,and water vapor transported mainly in north-south direction.Wind direction changed fast at the low level,which caused humidity increasing suddenly,thereinto,it was the main contribution of the south wind component.The vertical water vapor was transported from 850 hPa to upper level,the intensity of transportation falled into a decline below 850 hPa. With the heavy rain occurring,the vertical water vapor transportation changed,the lower the height,the higher the intensity of trans-portation,and water vapor flux reduced rapidly on surface in U and V direction.After the heavy rain,water vapor transportation on surface and upper layer changed.There was a corresponding relationship between the atmospheric precipitable water and precipitation. The atmospheric precipitable water in heavy rainstorm area primarily depended on the vapor flux convergence in horizontal direction, while vapor flux convergence was largely decided by convergence of horizontal wind.