利用局部高空间分辨率大气数据计算GRACE大气去混频模型

在计算GRACE重力场反演中的大气去混频模型时,针对ECMWFop或ERA-Interim大气数据空间水平分辨率不足的问题,提出了一种局部区域高空间水平分辨率大气数据与全球大气数据合理拼接融合的方法。利用欧洲局部区域的大气数据与ERA-Interim大气数据融合计算了一组改进的大气去混频模型,从谱域、空域及星间距离变率残差角度分析了改进大气去混频模型的质量。结果表明改进大气去混频模型相对于常规大气去混频模型的质量提高最大比例为1.87%,与AOD1BRL05相对于RL04的提高比例2.27%相当,验证了高空间水平分辨率大气数据确实有助于提高大气去混频模型质量的结论,为改进GRACE提取局部区域特定质量变化信号提供了一种方法。

Using High Spatial-resolution Regional Atmospheric Data for Computation of GRACE Atmospheric De-aliasing Models

Focusing on the problem that the spatial horizontal resolution of ECMWFop or ERA-Interim atmospheric data is not enough for the computation of atmospheric de-aliasing models in GRACE gravity recovery, a method of suitable fusion of local high spatial horizontal resolution atmospheric data and global atmospheric data is proposed.A set of improved atmospheric de-aliasing models is calculated by using the atmospheric data from the local area of Europe and ERA-Interim.The quality of the modified atmospheric de-aliasing models is analyzed from the aspects of spectral domain, spatial domain and satellite-to-satellite range-rate residuals.The results show that the improvement ratio of the improved atmospheric de-aliasing models is 1.87% compared with the conventional atmospheric de-aliasing models, which is comparable to that of the AOD1B RL05 relative to the RL04.It is verified that the atmospheric data with high spatial horizontal resolution could improve the quality of atmospheric de-aliasing models.So it provides a new approach to improve the ability to extract specific mass variation signal in local area using GRACE data.