维普中文期刊产品整合服务

Background Error Covariance Statistics of Hydrometeor Control Variables Based on Gaussian Transform

查看全文 作　　者：Tao [1]SUN;Yaodeng [1]CHEN;Deming [1]MENG;Haiqin [1]CHEN 高影响力作者 机构地区：[1]Key Laboratory of Meteorological Disaster of Ministry of Education(KLME)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters,Nanjing University of Information Science and Technology,Nanjing 210044,China高影响力机构 出　　处：《Advances in Atmospheric Sciences》索引2021年第38卷第5期,共14页高影响力期刊 基　　金：National Key Research and Development Program of China(Grant No.2017YFC1502102);National Natural Science Foundation of China(Grant No.42075148);Graduate Research and Innovation Projects of Jiangsu Province(Grant No.KYCX20_0910);the High-Performance Computing Center of Nanjing University of Information Science and Technology(NUIST). 摘　　要：Use of data assimilation to initialize hydrometeors plays a vital role in numerical weather prediction(NWP).To directly analyze hydrometeors in data assimilation systems from cloud-sensitive observations,hydrometeor control variables are necessary.Common data assimilation systems theoretically require that the probability density functions(PDFs)of analysis,background,and observation errors should satisfy the Gaussian unbiased assumptions.In this study,a Gaussian transform method is proposed to transform hydrometeors to more Gaussian variables,which is modified from the Softmax function and renamed as Quasi-Softmax transform.The Quasi-Softmax transform method then is compared to the original hydrometeor mixing ratios and their logarithmic transform and Softmax transform.The spatial distribution,the non-Gaussian nature of the background errors,and the characteristics of the background errors of hydrometeors in each method are studied.Compared to the logarithmic and Softmax transform,the Quasi-Softmax method keeps the vertical distribution of the original hydrometeor mixing ratios to the greatest extent.The results of the D′Agostino test show that the hydrometeors transformed by the Quasi-Softmax method are more Gaussian when compared to the other methods.The Gaussian transform has been added to the control variable transform to estimate the background error covariances.Results show that the characteristics of the hydrometeor background errors are reasonable for the Quasi-Softmax method.The transformed hydrometeors using the Quasi-Softmax transform meet the Gaussian unbiased assumptions of the data assimilation system,and are promising control variables for data assimilation systems. 关 键 词：hydrometeors control variables data assimilation background error covariance Gaussian transform
相关文献

参考文献(53)

引证文献(1)

网站首页 | 关于我们 | 联系我们 | 产品服务 | 客服中心 | 广告服务 | 版权声明 | 网站联盟 | 友情链接 | 售卡网点

版权所有© 渝B2-20050021-1　渝公网安备 50019002500403号　违法和不良信息举报中心

互联网出版许可证 新出网证(渝)字10号 全国400电话 - 免长途话费