台风“彩虹”过程的湿位涡分析  

Analysis of Moist Potential Vorticity During the Process of Typhoon Mujigea

作　　者：徐碧裕 叶朗明[1] 胡丽华[1] 

机构地区：[1]江门市气象局,广东江门529030

出　　处：《广东气象》2016年第4期7-11,共5页Guangdong Meteorology

摘　　要：采用NCEPFNL 1°×1°再分析资料、国家气候中心0.1°×0.1°降水融合资料以及地面观测站逐时雨量数据对台风"彩虹"过程湿位涡进行分析。结果表明:850 h Pa上MPV1正负值交界的等值线密集区、925 h Pa上MPV1负值区与强降水区域均有很好的对应关系;高层MPV1正值,低层负值,有利于能量下传,增强了对流层低层的不稳定度(即θe/p增加),导致不稳定能量释放;在台风中心附近有-θe/p≈0转为<0,有利于上升运动的发展;在低层MPV2正负值弱中心降雨均不明显,反而在正负值交界等值线密集区的近负值区域一侧降雨强度大,在一定程度上可根据MPV2的分布得出冷暖空气的相互作用。Using the FNL 1°×1° reanalysis of NCEP, 0.1°×0.1° rainfall integrated data from the National Climate Center and hourly rainfall data from surface observation stations, we studied the process of moist potential vorticity （MPV） during the visit by Typhoon Mujigea. The result is shown as follows. Good corresponding links are found between an 850-hPa area where dense positive and negative MPV1 contours meet and a 925-hPa area of negative MPV1 contours and the area of intense rain. MPV1 is positive at the upper level but negative at the low level, favoring the downward transport of energy and enhancing the instability of the lower troposphere （ i. e. δθe/δρincreases） to result in the release of instability energy. Around the center of Murigea, -δθe/δρ≈0 transformed into - δθe/δρ〈 0, favoring the development of ascending motion. At the low level, rain was insignificant at the centers of positive and negative MPV2 but very intense on the side of a negative area where dense contours of positive and negative MPV2 met. To some extent, the interaction between cold and warm air can be known from the distribution of MPV2.

关 键 词：天气学 湿位涡 台风“彩虹” 倾斜涡度发展理论 

分 类 号：P458[天文地球—大气科学及气象学]