夏季鄱阳湖上空对流系统减弱过程分析  

Analysis on Weakening Process of Convective System Passing over Poyang Lake in Summer

作　　者：傅敏宁[1,2] 郑有飞[1] 邹海波[2] 刘熙明[2] 

机构地区：[1]南京信息工程大学,江苏南京201144 [2]江西省气象科学研究所,江西南昌330046

出　　处：《高原气象》2013年第3期865-873,共9页Plateau Meteorology

基　　金：国家自然科学基金项目(41265003;40965001);中国气象科学研究院灾害天气国家重点实验室基金项目(2009LASW-A02);江西省2009年度自然科学基金项目(2009GZH0051)共同资助

摘　　要：利用6h一次的NCEP分析资料和南昌站新一代多普勒天气雷达6min一次的组合反射率资料,分析了2007年7月23日10:00-16:00(北京时)江西西北部幕阜山脉上空对流云团东移经过鄱阳湖主体时明显减弱或消亡过程。同时,利用中尺度非静力模式WRF对这次过程分别进行了控制性试验(CTR)和敏感性试验(SES)。结果表明,CTR试验能较好地模拟出对流云团经过鄱阳湖时的减弱过程;与CTR试验相比,SES试验模拟的鄱阳湖区向外长波辐射值明显偏低,表明鄱阳湖的存在对过境对流云团有减弱作用;两试验的地表比热差异造成CTR(SES)试验模拟的地面感热和潜热通量较低(较高);CTR试验还模拟出负的地面感热通量,即感热从大气向湖体传递;两试验模拟的地面能量通量的差异导致鄱阳湖主体低层(950hPa)的风场差异显著,即在鄱阳湖主体上空出现了一反气旋性环流,鄱阳湖对过境对流云团的减弱作用是该反气旋环流的辐散下沉造成的。Using NCEP FNL analysis data and Doppler radar composition reflectivity data of Nanchang, the convection systems passing over Poyang Lake in summer was analyzed. The results show that the convec- tions generated over Mufu Mountains, which is located in northwest Jiangxi, weaken or dissipate during 10：00--16：00 on 23 July 2007 when they pass over Poyang Lake. Based on the double nestedWRFV3.2 model, CTR （control experiment which includes Poyang Lake in the second nest） and SES （sensitive ex- periment which does not include Poyang lake in the second nest） experiments are performed to simulate this process. The simulated results show that CTR experiment could successfully simulate the weakened process of convection activities passing over Poyang Lake. Comparing with the results of CTR experiment, the outgoing long wave radiation （OLR） value simulated by SES experiment is significant larger over Poy- ang Lake, it means that the Poyang Lake could weaken the convection activities. The difference of surface specific heat capacity between the two experiments results in smaller （larger） sensitive heat flux and latent heat flux in CTR （SES） experiment over Poyang Lake, which brings a significant difference of wind field at low level （950 hPa） between two experiments, there is an anti-cyclonical circulation of the anomaly wind field （CTR minus SES） over Poyang Lake, the divergence and subsidence processes associated with the an- ti-cyclonical circulation eventually cause the weakening of convection activities passing over Poyang Lake.

关 键 词：WRF模式 对流活动 向外长波辐射 热通量 鄱阳湖 

分 类 号：P435.2[天文地球—大气科学及气象学]