利用中国CRA-40再分析数据计算大气去混频模型及其质量评估  

Computation and Mass Assessment Concerning Atmospheric Dealiasing Models Using CRA-40 Reanalysis Dataset

作　　者：熊大伟 游为 余彪 刘充 范东明 XIONG Dawei;YOU Wei;YU Biao;LIU Chong;FAN Dongming(Faculty of Geosciences and Environmental Engineering,Southwest Jiaotong University,Chengdu611756,China)

机构地区：[1]西南交通大学地球科学与环境工程学院,四川成都611756

出　　处：《武汉大学学报(信息科学版)》2025年第4期727-738,共12页Geomatics and Information Science of Wuhan University

基　　金：国家自然科学基金(41974013,42174014)。

摘　　要：大气与海洋非潮汐高频质量变化是时变重力场反演过程中需要精确建模并提前扣除的重要误差来源,随着中国重力卫星计划的推进,实现这一地球重力场背景力模型的国产化具有重要意义。比较中国第一代全球大气再分析产品(40 year global reanalysis dataset released by China Meteorological Administration,CRA-40)的表面压力与温度数据,结果表明其数据质量与第三代全球再分析产品相当。以CRA-40为输入数据计算了一套大气去混频(atmospheric dealiasing,AD)模型CRA-40-AD,从球谐系数、星间距离变率残差、反演时变重力场3个层面评估其质量。评估结果表明,CRA-40-AD与德国地学研究中心AOD1B RL06(RL06)在谱域以及时域相关性较好,与RL06的谱域差距在约20阶之后小于重力恢复与气候实验(gravity recovery and climate experiment,GRACE))的模拟精度;CRA-40-AD与RL06的星间距离变率残差均方根差异不足20 nm/s,满足当前GRACE K波段测距系统的精度;CRA-40-AD与RL06反演时变重力场的大地水准面高阶方差曲线的数值差异在0~0.6 mm之间,满足地球重力场1 mm的大地水准面精度要求。对CRA-40大气再分析计算大气AD模型的多方验证表明CRA-40-AD模型满足当前时变重力场反演的要求,有望实现大气AD产品的完全国产化。Objectives Atmospheric and oceanic non-tidal high-frequency mass variations constitute a primary source of error that need to be accurately modeled and removed before the process of time-variable gravity field inversion.The advancement of China's gravity satellite mission makes achieving the domestic production of the background force model for the Earth's gravity field highly meaningful.Methods The 40 year global reanalysis dataset released by China Meteorological Administration(CRA-40)is China's first generation of reanalysis products.The evaluation of surface pressure and temperature illustrates that its quality is comparable to the third generation of global reanalysis on the basis of the comparisons we make.A set of AD(atmospheric dealiasing)models,CRA-40-AD,is calculated by using CRA-40 as input data.To investigate the applicability of employing CRA-40 to calculate AD model,the validation of resulted models is carried out from three aspects including spherical harmonic coefficients,K-band range rate(KBRR)residuals and geoid heights derived from time-variable gravity field models.Results The results of the evaluations indicate that CRA‑40-AD exhibit a strong correlation with GFZ AOD1B RL06(RL06)in both spectral and time domains.The differences between CRA‑40-AD and RL06 in spectral domain are smaller than the GRACE simulation accuracy after 20 orders.The root mean square differences of KBRR residuals between CRA-40-AD and RL06 are below 20 nm/s,which conforms to the accuracy of gravity recovery and climate experiment(GRACE)K-band ranging system.The differences in geoid degree between CRA-40-AD and RL06 range from 0 to 0.6 mm,which satisfies the 1 mm geoid accuracy.Conclusions Consequently,CRA-40 has been shown to have the potential to be used in AD models,making the fully localization of AD products promising to achieve.

关 键 词：AD模型 CRA-40 再分析数据集 重力场模型 GRACE 质量评估 

分 类 号：P223[天文地球—大地测量学与测量工程]