适应数值模式垂直坐标的GPS掩星反演资料稀疏化方案  

A new thinning scheme of GPS occultation retrieved data for the vertical coordinates of a numerical model

作　　者：马旭林[1] 郭欢[1,2] 和杰 周勃旸[1] 李琳琳 MA Xulin;GUO Huan;HE Jie;ZHOU Boyang;LI Linlin(Key Laboratory of Meteorological Disaster of Ministry of Education(KLME),Nanjing University of Information Science & Technology,Nanjing 210044,China;China Institute for Radiation Protection,Taiyuan 030006,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,江苏南京210044 [2]中国辐射防护研究院,山西太原030006

出　　处：《大气科学学报》2019年第3期380-389,共10页Transactions of Atmospheric Sciences

基　　金：国家重点研发计划(2018YFC1506702; 2017YFC1502000);公益性行业(气象)科研专项(GYHY201506005)

摘　　要：GPS掩星反演大气温湿资料具有高垂直分辨率、高精度、受云和降水影响小等优点,针对GRAPES同化预报系统,发展设计了一种既考虑预报模式高度-地形追随垂直坐标不均匀分层特点,又结合掩星反演资料特性的新适应性垂直稀疏化方案。通过个例试验和批量试验,探索了该适应性稀疏化方案对分析预报质量的影响。试验结果表明:选取合适的稀疏参数,新稀疏化方案的GPS掩星反演资料对背景场的调整更加有效,分析场质量更高;位势高度、比湿、温度和风场等预报场的均方根误差均更小;适应性稀疏化方案对改善台风路径预报具有积极作用。批量试验则进一步证实了适应性稀疏化方案对分析场质量有明显的改善作用。There are some advantages of high vertical resolution,including its high accuracy and the fact that it is less significantly affected by cloud and precipitation for GPS(Global Positioning System) radio occultation data.In the present study,a new adaptive vertical thinning scheme,which considers both the non-uniform layered characteristics of height-terrain following vertical coordinates and the features of radio occultation retrieved data,is developed so as to avoid redundancy of observations data in assimilating for regional GRAPES m3DVAR.The new thinning scheme for GPS radio occultation data is able to accord to the vertical coordinates of the GRAPES m3DVAR assimilation system and the characteristics of the vertical levels,so as to reasonably select the GPS occultation data and eliminate redundant data.The thinning scheme can improve the adjustments of the observations to the background fields for the assimilation of GPS occultation data,thereby effectively improving the subsequent assimilation analysis quality and prediction skill.A case experiment and batch test are performed to explore the impact of the new adaptive thinning scheme on the quality of analysis and forecast field.The study results indicate that GPS radio occultation data retrieved using the new adaptive thinning scheme lead to greater adjustments in the background fields,higher quality analysis,and smaller root-mean-square error of prediction of geopotential height,temperature,specific humidity and wind field,if the suitable sparse parameters are selected.In addition,the adaptive thinning scheme has a positive effect on improving the forecast of typhoon tracks.The results of the batch experiments have confirmed that the analysis field quality with the adaptive thinning scheme yields a significant improvement for the assimilation of temperature and vapor pressure retrieved from GPS radio occultation data.

关 键 词：资料同化 三维变分 GRAPES GPS掩星 COSMIC 垂直稀疏化 

分 类 号：P228.4[天文地球—大地测量学与测量工程]