2015年1月西北太平洋上一个爆发性气旋“眼”的结构分析  

Analyses of “Eye” of an Explosive Cyclone over the Northwestern Pacific in January,2015

作　　者：陈莅佳 傅刚 CHEN Li-Jia;FU Gang(Department of Marine Meteorology,College of Oceanic and Atmospheric Science,Ocean University of China,Qingdao 266100,China)

机构地区：[1]中国海洋大学海洋与大气学院海洋气象系,山东青岛266100

出　　处：《中国海洋大学学报（自然科学版）》2018年第12期7-14,共8页Periodical of Ocean University of China

基　　金：国家自然科学基金项目(41275049;41775042)资助~~

摘　　要：利用美国国家环境预报中心(National Centers for Environmental Prediction,简称NCEP)提供的最终客观分析(Final Analysis,简称FNL)资料、NCEP气候预报系统第二版(Climate Forecast System version 2,简称CFSv2)格点资料和美国热带气旋中心(Cooperative Institute for Meteorological Satellite Studies,简称CIMSS)提供的红外卫星云图资料,对2015年1月发生在西北太平洋上的一个爆发性气旋进行了研究,对其演变过程及环流形势进行了分析,并利用高分辨率卫星云图资料对该气旋发展过程中形成的似"盘蜷的蛇"状分布的"眼"区结构进行了分析。结果表明,气旋在发展过程中,地面气旋中心位于500hPa槽前,较强的正涡度平流和大气斜压性使得气旋爆发性发展。高空急流提供的辐散和低空水汽输送也在气旋爆发性发展过程中起到了重要的作用。该气旋在发展过程中出现了与热带气旋相类似的"眼"状结构,在眼区内有"暖心"结构和下沉运动区;在气旋达到成熟前6h,卫星云图上在气旋中心出现了轮廓清晰且未闭合的"眼";在气旋成熟时,云团在"眼"的内部向内旋转数圈形成一个"盘蜷的蛇"状分布;在达到成熟后10h内,350hPa上的涡度和位势涡度都出现了与卫星云图相类似的结构。而卫星云图上云系的这种分布可能与高空的气旋中心的位势涡度的水平分布有关,也即云系是高空位势涡度的动力学作用的反映。In this paper,an explosive extratropical cyclone(EC)with a clear“eye”structure over the Northwestern Pacific in January 2015 was investigated by using the Final Analysis(FNL)data and Climate Forecast System version 2(CFSv2)data from National Centers for Environmental Prediction(NCEP),as well as the infrared satellite imagery from Cooperative Institute for Meteorological Satellite Studies(CIMSS).The evolutionary process of this EC and the synoptic conditions which led to its genensis were analyzed.The“eye”structure which looked like“a curled snake”from satellite imagery was examined by using high-resolution data.The results showed that the cyclone center located at the front of a trough at 500 hPa at the development stage of the cyclone.Stronger advection of positive vorticity and atmospheric baroclinicity played the dominate role during this stage.Divergence caused by upper-level jet and transport of water vapor at low level played an important role during the development of the cyclone.An“eye”structure with warm core and subsiding area,similar to a tropical cyclone eye,was observed,6 hours before the cyclone reaching its maturity,together with a clear but not closed“eye”structure in the satellite image.When the cyclone was at mature stage,the clouds near the“eye”region rotated inwards several laps to form a“curled snake”shaped distribution.10 hours later,the relative vorticity and potential vorticity at 350 hPa appeared a similar structure with satellite imagery.The pattern of the clouds may be related to the distribution of potential vorticity around the cyclone center,which indicated that the clouds may be reflection of the dynamic effect of potential vorticity.

关 键 词：爆发性气旋 天气形势分析 位势涡度 “眼”状结构 

分 类 号：P443[天文地球—大气科学及气象学]