CAJ | 학술논문

采用2008年我国南方暴雨野外科学试验(SCHeREX)加密资料和NCEP再分析资料、FY-2C卫星TBB资料以及常规观测资料对广西致洪暴雨进行了研究.研究发现,西南涡是此次暴雨过程的直接影响系统,对流和降水主要发生在低涡的中部及其东南方.中高纬切断低压和副热带高压稳定维持,500 hPa短波槽沿高原东侧南下,诱导西南涡向东南移入广西,这种情况并不太常见,这是由于槽后冷空气活跃,但路径偏西.受副热带高压西伸影响,低槽与西南低涡移动缓慢.在移入广西前西南涡一度减弱,但由于有明显的中、低纬系统相互作用存在,季风槽为本次暴雨输送了充沛的水汽,致使西南涡再度加强,引发暴雨.暴雨过程中中尺度对流云团活动频繁,强度大,降水强,有大约11个中尺度雨团缓慢移动.桂林的探空资料表明,暴雨区中低层温度层结多为中性,这可能是对流混合的结果,西南涡过境后,低层风场有明显变化,大气抬升凝结高度显著降低,对流有效位能(CAPE)由于释放而降低.在上述研究的基础上,本文提出了一类华南前汛期低涡切变型暴雨概念模型.
채용2008년아국남방폭우야외과학시험(SCHeREX)가밀자료화NCEP재분석자료、FY-2C위성TBB자료이급상규관측자료대엄서치홍폭우진행료연구.연구발현,서남와시차차폭우과정적직접영향계통,대류화강수주요발생재저와적중부급기동남방.중고위절단저압화부열대고압은정유지,500 hPa단파조연고원동측남하,유도서남와향동남이입엄서,저충정황병불태상견,저시유우조후랭공기활약,단로경편서.수부열대고압서신영향,저조여서남저와이동완만.재이입엄서전서남와일도감약,단유우유명현적중、저위계통상호작용존재,계풍조위본차폭우수송료충패적수기,치사서남와재도가강,인발폭우.폭우과정중중척도대류운단활동빈번,강도대,강수강,유대약11개중척도우단완만이동.계림적탐공자료표명,폭우구중저층온도층결다위중성,저가능시대류혼합적결과,서남와과경후,저층풍장유명현변화,대기태승응결고도현저강저,대류유효위능(CAPE)유우석방이강저.재상술연구적기출상,본문제출료일류화남전신기저와절변형폭우개념모형.
Based on observations from the South China Heavy Rainfall Experiment(SCHeREX)and the reanalysis data from NCEP/NCAR,one kind of vortex with heavy rainfall during pre-rainy season in South China(1200 UTC 10June-0000 UTC 13June 2009)is analyzed,and the results are as follows.The southwest vortex(SWV)was the direct influencing system of heavy rainfall,convective activities and precipitation were always at the center or to the southeast of the southwest vortex.The rain areas moved from west to east with the southwest vortex and the short-wave trough.Convective clouds were active during this rainfall(some of them are meso-α-scale or meso-β-scale sys-tems,respectively)and there were about 11 meso-scale rain clusters,which remained quasi-stationary or moved slowly.Neutral stratification,sometimes with thermal inversion,was located at the middle to low levels.After the southwest vortex moved out,wind at low levels changed remarkably,and the convective available potential energy (CAPE)decreased.The long persistence of cut-off low and subtropical high contributed to the stable maintenance of circulation.The short-wave trough at 500 hPa moved southward along the Tibetan Plateau,leading the southwest vortex to move southeastward to Guangxi.Influenced by the subtropical high,the trough was quasi-stationary,and after 0000 UTC 13 June,as the subtropical high retreated,the trough moved eastward.During the heavy rainfall,there were obviouS interactions between middle and low latitude systems:the cold air was active,and the monsoon trough transported enough moisture to Guangxi,which enhanced the SWV.Based on the above researches,the schematic model of one kind of vortex causing heavy rainfall has been proposed.