FY-4A卫星云导风观测误差优化及同化效果影响研究  

A study of the observational error statistics and assimilation applications of the FY-4A satellite atmospheric motion vector

作　　者：陈耀登[1] 沈洁[1] 范水勇[2] 王程 CHEN Yaodeng;SHEN Jie;FAN Shuiyong;WANG Cheng(Key Laboratory of Meteorological Disaster,Ministry of Education(KLME)/Joint International Research Laboratory of Climate and Environment Change(ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disaster(CIC-FEMD),Nanjing University of Information Science & Technology,Nanjing 210044,China;Institute of Urban Meteorology,CMA,Beijing 10089,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]中国气象局北京城市气象研究所,北京10089

出　　处：《大气科学学报》2021年第3期418-427,共10页Transactions of Atmospheric Sciences

基　　金：国家重点研发计划项目(2017YFC1502102,2018YFC1506803);国家自然科学基金项目(42075148)。

摘　　要：为了推进FY-4A卫星资料在数值模式中的实际应用,本研究选择云导风产品作为研究对象,首先统计了FY-4A高层水汽通道和红外通道云导风的观测误差,进一步基于WRFDA(Weather Research and Forecasting model Data Assimilation system)系统,利用默认观测误差和新观测误差进行了为期一个月的循环同化及预报试验,并分析了试验期间的台风预报效果。结果表明:相较于默认观测误差,FY-4A云导风产品的新观测误差垂直结构特征更加明显;采用本研究统计的FY-4A云导风观测误差,能够在默认观测误差的基础上改善风场的分析和预报效果;试验期间的两个台风个例分析表明,新观测误差也能够减小台风路径的预报误差。The data from the FY-4A satellite have a higher temporal and spatial resolution when compared with the data obtained from the FY-2 satellites.This indicates the recent development of China's geostationary meteorological satellites.In order to promote the practical applications of the FY-4A satellite data in a model and investigate the impacts of observational errors on the assimilation and forecasting accuracy of the atmospheric motion vector(AMV)of the FY-4A satellite,this study carried out in-depth research experiments.The observational errors of the AMVs derived from the high-level water vapor channels and infrared channels of the FY-4A were first calculated and analyzed.The vertical profiles revealed that when compared with the default observational errors of the assimilation system,the new observational errors of the high-level water vapor channel had decreased with height between 700 hPa and 200 hPa.In addition,the new observational errors of the infrared channels were smaller below 800 hPa than above 700 hPa,where the vertical structural features were more pronounced.A series of assimilation and forecasting experiments were carried out using the default observational errors and the new observational errors.It was determined that according to the average RMSE profiles,the results using the new errors were significantly improved in the wind field when compared with results using the default errors.At the same time,the heights at which the RMSE of the wind field had displayed maximum improvement corresponded to the heights at which the number of observations were the largest.Also,the new observational errors of the infrared channels were observed to more widely influence the wind field than that of the high-level water vapor channels since the data from the infrared channels were distributed on almost every layer.Furthermore,the track and intensity forecasting results of the“Hato”and“Pakhar”typhoon systems were discussed in this study in order to further examine the impacts of observational errors on

关 键 词：资料同化 FY-4A 云导风 观测误差 

分 类 号：TP3[自动化与计算机技术—计算机科学与技术]