基于云顶高度产品的FY-4A云导风高度再指定方法研究  

Height Reassignment Method of FY-4A Atmospheric Motion Vectors Based on Cloud Top Height Products

作　　者：马博良 陆其峰[2,3] 王富 华维 张晓虎[5,6,7] MA Boliang;LU Qifeng;WANG Fu;HUA Wei;ZHANG Xiaohu(School of Atmospheric Sciences,Chengdu University of Information Technology,Chengdu 610225;Earth System Modeling and Prediction Centre,CMA,Beijing 100081;State Key Laboratory of Severe Weather,Chinese Academy of Meteorological Sciences,Beijing 100081;Wenjiang National Climatology Observatory,Chengdu 611133;National Satellite Meteorological Centre/National Centre for Space Weather,Beijing 100081;Innovation Center for FengYun Meteorological Satellite(FYSIC),Beijing 100081;Key Laboratory of Radiometric Calibration and Validation for Environmental Satellites,CMA,Beijing 100081)

机构地区：[1]成都信息工程大学大气科学学院,成都610225 [2]中国气象局地球系统数值预报中心,北京100081 [3]中国气象科学研究院灾害天气国家重点实验室,北京100081 [4]温江国家气候观象台,成都611133 [5]国家卫星气象中心/国家空间天气监测预警中心,北京100081 [6]许健民气象卫星创新中心,北京100081 [7]中国气象局遥感卫星辐射测量和定标重点开放实验室,北京100081

出　　处：《气象》2025年第4期484-495,共12页Meteorological Monthly

基　　金：国家重点研发计划(2022YFC3004102);温江国家气候观象台科研团队建设计划共同资助。

摘　　要：高度指定误差是卫星导风产品最主要的误差来源。FY-4A云顶高度产品采用红外窗区通道和二氧化碳切片通道算法,精度较高。将FY-4A云顶高度与云导风产品进行时空匹配,在云导风目标追踪框中搜索代表性像元,用其平均云顶高度替换原有云导风的云高,实现其高度再指定。基于ERA5再分析资料的检验结果表明:高度再指定后,高、中、低三层的FY-4A云导风均方根误差均有明显降低,分别从4.06 m·s^(-1)降至3.25 m·s^(-1),4.25 m·s^(-1)降至3.71 m·s^(-1),2.42 m·s^(-1)降至2.13 m·s^(-1)。高度再指定缓解了云导风定高偏高的问题,降低了云导风偏差,特别是慢速偏差改善明显。东北冷涡和台风暹芭等个例表明该方法能够提高云导风与背景场的一致性,在数值预报同化和天气过程分析中具有较好的应用前景。The primary source of the bias of atmospheric motion vectors(AMVs)is related to inaccuracies in assigning heights.The cloud top height algorithm employed by China’s new generation geostationary meteorological satellite FY-4A make use of both the infrared window channel and CO 2 slicing channel.This leads to an improvement in its accuracy.In this study,cloud top height is used to correct AMVs of FY-4A satellite through spatiotemporal matching between the two products.Representative pixels within the AMVs tracking box are searched,and their average cloud top height is used to replace the original cloud height of the AMVs,achieving height reassignment.Verification using ERA5 reanalysis data shows that after height reassignment,the root mean square error(RMSE)of FY-4A infrared channel AMVs is significantly reduced across high,medium,and low layers.Specifically,the RMSE for the high layer decreases from 4.06 m·s^(-1)to 3.25 m·s^(-1),for the medium layer from 4.25 m·s^(-1)to 3.71 m·s^(-1),and for the low layer from 2.42 m·s^(-1)to 2.13 m·s^(-1).Height reassignment alleviates the problem of AMVs being assigned to overly high altitudes,reducing biases,particularly improving slow motion biases.Case studies of the Northeast China cold vortex and Typhoon Chaba demonstrate that this method can improve the consistency between cloud-derived winds and the background field.Promising applications of this method in numerical weather prediction assimilation and weather process analysis are envisioned.

关 键 词：云导风 云顶高度 高度再指定 代表运动像元 FY-4A 

分 类 号：P413[天文地球—大气科学及气象学]