利用卫星微波观测亮温监测东北冷涡移动路径  

A comparative study on the movement paths of Northeast China cold vortex between satellite microwave observations and all-sky simulations

作　　者：毛严 邹晓蕾[1] 董慧杰 MAO Yan;ZOU Xiaolei;DONG Huijie(Joint Center of Data Assimilation for Research and Application,Nanjing University of Information Science&Technology,Nanjing 210044,China)

机构地区：[1]南京信息工程大学资料同化研究与应用联合中心,南京210044

出　　处：《气象科学》2024年第6期1122-1133,共12页Journal of the Meteorological Sciences

基　　金：国家重点研发计划资助项目(2018YFC1506702)。

摘　　要：再分析资料已被广泛应用于东北冷涡的研究。这些冷涡常发生在春末夏初,引起低温和雷暴。本文利用MetOp-B先进微波温度探测仪(Advanced Microwave Sounding Unit-A,AMSU-A)的对流层高层通道亮温观测追踪2020年5—7月4个东北冷涡的移动路径。权重函数峰值分别位于250和200 hPa高度的AMSU-A通道7和8的亮度观测具有明显的东北冷涡暖核结构,其时间演变反映平流层空气的持续向南和向下入侵。因此,东北冷涡的移动路径可以根据AMSU-A通道7和8的亮温观测暖核中心位置来确定。虽然再分析资料同化了无线电探空资料以及AMSU-A等其他卫星观测,但依据AMSU-A单个仪器的观测亮温得到的4个东北冷涡的移动路径与实况分析和ERA5全天空模拟亮温得到的一致。4个东北冷涡都起源于西伯利亚中部,向东南移动至不同纬度后再转向东、东南或东北移动。MetOp-B是一颗上午星,每日提供两次全球观测。若与晨昏星(FY-3E)和下午星(FY-3D或NOAA-20)构成三轨星座,则可实现对东北冷涡的移动路径每天6次的实时观测。Reanalysis data had extensively employed for investigating of Northeast China Cold Vortices(NCCVs),which frequently occur in late spring and early summer and cause cold temperature and thunderstorms.In this study,the MetOp-B Advanced Microwave Sounding Unit-A(AMSU-A)brightness temperature observations in the upper troposphere were used to track the movement paths of NCCV.Four NCCV cases that occurred in May,June and July 2020 were selected.The brightness temperature observations at AMSU-A channels 7 and 8,whose peak weighting function are located near 250 and 200 hPa vertical levels,respectively,have clear warm core structures,whose temporal evolutions followed a continuing southward and downward intrusion of stratospheric air of NCCVs.The movement paths of NCCV can thus be determined by the center positions of warm cores of brightness temperature observations at AMSU-A channels 7 and 8.The moving paths of the four NCCVs compared favorably with the ERA5 all-sky simulations and operational analysis,which had drawn high-vertical-resolution radiosondes and satellite observations including AMSU-A.Originating in central Siberia,the movement paths of four NCCVs headed southeastward,reaching different latitudes before heading eastward,southeastward or northeastward.MetOp-B is a morning orbit satellite which provides global observations twice daily.Together with microwave temperature-sounding instruments onboard an early-morning(FY-3E)and an afternoon orbit(FY-3D or NOAA-20)satellites,an NCCV moving path can be monitored six times daily with a three-orbit constellation in real time.

关 键 词：星载微波温度计 全天空模拟亮温 东北冷涡 移动路径 临边订正 

分 类 号：P407.7[天文地球—大气科学及气象学]