气象与环境学报
氣象與環境學報
기상여배경학보
Journal of Meteorology and Environment
2015年
4期
1-6
,共6页
不稳定能量%假相当位温%对流有效位能%能量廓线
不穩定能量%假相噹位溫%對流有效位能%能量廓線
불은정능량%가상당위온%대류유효위능%능량곽선
Instability energy%Pseudo-equivalent temperature%Convective available energy%Energy profile
利用常规气象观测站、地面加密自动站及 NCEP 再分析资料对2012年7月21日北京地区特大暴雨（简称“7.21”过程）不稳定能量进行诊断分析。结果表明：北京地区“7.21”暴雨过程中西南低空急流对水汽和不稳定能量的输送使对流有效位能迅速增加；暴雨发生时假相当位温的垂直分布几乎与等压面垂直，暴雨过程中伴有大量的凝结潜热释放，对对流层中层起到加热作用，甚至出现了位势稳定的情况。单站探空资料的分析表明，低层存在明显的逆温层，有利于前期不稳定能量的积累；暴雨发生前对流有效位能达2089 J·kg －1，能量平衡高度为160 hPa，正超能的分析也表明北京地区“7.21”过程为特大暴雨的能量特征。当强度为1.2×10－4 s 的气旋性涡度靠近北京地区时，有利于不稳定能量的释放。
利用常規氣象觀測站、地麵加密自動站及 NCEP 再分析資料對2012年7月21日北京地區特大暴雨（簡稱“7.21”過程）不穩定能量進行診斷分析。結果錶明：北京地區“7.21”暴雨過程中西南低空急流對水汽和不穩定能量的輸送使對流有效位能迅速增加；暴雨髮生時假相噹位溫的垂直分佈幾乎與等壓麵垂直，暴雨過程中伴有大量的凝結潛熱釋放，對對流層中層起到加熱作用，甚至齣現瞭位勢穩定的情況。單站探空資料的分析錶明，低層存在明顯的逆溫層，有利于前期不穩定能量的積纍；暴雨髮生前對流有效位能達2089 J·kg －1，能量平衡高度為160 hPa，正超能的分析也錶明北京地區“7.21”過程為特大暴雨的能量特徵。噹彊度為1.2×10－4 s 的氣鏇性渦度靠近北京地區時，有利于不穩定能量的釋放。
이용상규기상관측참、지면가밀자동참급 NCEP 재분석자료대2012년7월21일북경지구특대폭우（간칭“7.21”과정）불은정능량진행진단분석。결과표명：북경지구“7.21”폭우과정중서남저공급류대수기화불은정능량적수송사대류유효위능신속증가；폭우발생시가상당위온적수직분포궤호여등압면수직，폭우과정중반유대량적응결잠열석방，대대류층중층기도가열작용，심지출현료위세은정적정황。단참탐공자료적분석표명，저층존재명현적역온층，유리우전기불은정능량적적루；폭우발생전대류유효위능체2089 J·kg －1，능량평형고도위160 hPa，정초능적분석야표명북경지구“7.21”과정위특대폭우적능량특정。당강도위1.2×10－4 s 적기선성와도고근북경지구시，유리우불은정능량적석방。
Based on the conventional observation data,the intensive meteorological data from automatic weather stations and the NCEP reanalysis data,the instability energy of a heavy rain process on July 21,2012 (called"7.21")in Beijing region was analyzed.The results show that water vapor and instability energy transported by southwest low level jet make the convective available potential energy increasing quickly during the process.Verti-cal distribution of the pseudo-potential temperature contours is nearly perpendicular to the isobaric surface when the heavy rainstorm occurs.There is a lot of latent heat releasing during the process,and it is of heating action for mid-dle troposphere and even stabilizes atmosphere potential.Analysis of sounding data from a single station suggests that there is a significant inversion temperature in low level,which is favorable to accumulation of instable energy. The convective available potential energy can reach 2089 J·kg -1 before heavy rainstorm occurs and the energy bal-ance height is 160 hPa.Analysis of positive super energy also suggests that there is energy feature of heavy rain-storm for the "7.21"process in Beijing region.When the cyclonic vortex with intensity of 1.2 ×10 -4 s is close to Beijing,it is favorable to release potential instability energy.
