雷达径向风资料EnKF同化应用对Vicente(2012)登陆台风强度变化过程预报的影响试验研究  

IMPACTS OF THE ENSEMBLE ASSIMILATION OF RADAR RADIAL VELOCITY ON THE INTENSITY EVOLUTION OF LANDFALLING TYPHOON VICENTE(2012)

作　　者：朱磊[1,2] 万齐林[2] 刘靓珂 沈新勇[1,3] 高郁东[2] ZHU Lei WAN Qi-lin LIU Liang-ke SHEN Xin-yong GAO Yu-dong(Key Laboratory of Meteorological Disaster, Ministry of Education/Joint International Research Laboratory of Climate and Environment Change/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of Information Science and Technology, Nanjing 210044, China Key Laboratory of Regional Numerical Weather Prediction, Guangzhou Institute of Tropical and Marine Meteorology, Guangzhou 510640, China Laboratory of Cloud-Precipitation Physics and Severe Storms Institute of Atmospheric Physics Chinese Academy of Sciences, Beijing 100029, China)

机构地区：[1]南京信息工程大学气象灾害教育部重点实验室/气候与环境变化国际合作联合实验室/气象灾害预报预警与评估协同创新中心,江苏南京210044 [2]中国气象局广州热带海洋气象研究所/广东省区域数值天气预报重点实验室,广东广州510640 [3]中国科学院大气物理研究所云降水物理与强风暴重点实验室,北京100029

出　　处：《热带气象学报》2017年第3期345-356,共12页Journal of Tropical Meteorology

基　　金：科技部国家大气污染专项项目(2016YFC0203301);国家重点基础研究发展计划973项目(2015CB453201);国家自然科学基金项目(41375058;41475102;41530427);江苏省自然科学基金重点项目(BK20150062)共同资助

摘　　要：探索了基于WRF模式的集合卡尔曼滤波同化方法(WRF-EnKF,简称EnKF)在近海有可能达到更强台风连续循环同化中国大陆高时空分辨率多普勒天气雷达径向风观测资料的效果,同时检验台风Vicente(2012)的三维结构演变及其动力学特征。通过短期集合预报得到跟随当前流场变化着的背景误差协方差的台风涡旋和动力学结构。研究发现,EnKF同化预报系统能有效地同化高时空分辨率雷达径向速度观测资料,显著改善初始场中台风Vicente的中小尺度内核结构,同时提高对台风Vicente的路径和强度及其相伴随的短期强降水预报。在台风最强时刻同化雷达径向风观测能快速(1~2 h)得到真实的暖核台风结构,同时进一步提高台风路径和强度的预报。另外,EnKF同化雷达径向风观测资料还能有效提高短期降水预报,1 h和3 h累积降水的分布、降水中心以及降水随时间演变都能得到显著改善,这与改善台风路径、结构和强度有密切关系。因此,对中国东南沿海有可能达到较强的台风进行同化雷达径向风观测资料可改善登陆台风的预报水平,这为利用我国地基多普勒天气雷达观测资料改善模式的初始场从而提高台风预报提供一定的指示作用。The current study explores the use of a WRF-based ensemble Kalman filter （EnKF） to continuously assimilate the high-resolution Doppler radar data near the peak stage in order to capture the detailed time evolution and the 3-D structure and dynamics of the recent Typhoon Vicente （2012） that made landfall during 2000 UTC 23 July 2012 near the Pearl River Delta region of Guangdong Province of China. With vortex and dynamics dependent background error covariance estimated by the short-term ensemble forecasts, it is found that the WRF-EnKF can efficiently assimilate the high resolution radar radial velocity to improve the depiction of the typhoon inner-core structure of Vicente which further improves the forecasts of the track, intensity and precipitation associated with this landfalling typhoon. We further use the WRF-EnKF analysis and forecasts along with the ensembles initialized from the EnKF perturbations at different time to examine the dynamics of Vicente with respect to the number of volumes of radar observations being assimilated, different lead time before and during the landfall. We are particularly interested in the heavy rainfall associated with the landfalling Vicente which affects a large area of South China. The results show that assimilating the Doppler Radar data is a very promising way to improve the TC forecasts, which also demonstrate that doing data assimilation near the peak stage of TC also has the ability to improve the forecast.

关 键 词：热带气旋 雷达径向风 集合卡尔曼滤波 

分 类 号：P456.7[天文地球—大气科学及气象学]