不同去相关方法对GRACE反演长江流域陆地水储量变化的影响

Effects of Different Decorrelation Methods on GRACE Inversion of Terrestrial Water Storage in the Yangtze River Basin

由于GRACE卫星轨道的设计和传感器误差以及球谐系数的相关性等因素的影响,利用GRACE数据解算的原始时变引力场模型中包含明显的南北方向条带误差,在一定程度上掩盖了真实的陆地水储量变化信号。针对不同的去相关方法反演的陆地水储量变化结果不同,且关于长江流域不同去相关方法之间的比较研究相对较少,以长江流域为研究区,选取SWENSON、P3M6、P4M15三种去相关方法,分析比较反演陆地水储量变化的结果。结果表明,在空间分布上,P3M6和P4M15方法空间分布较为接近,P4M15信号损失较多,SWENSON虽然保留了较多的信号,但其空间分布与其余两种方法相差较大,可能与经验参数选取有关。在时间域上,陆地水储量变化周年项振幅大小顺序为P4M15>P3M6>NONE(不进行去相关处理)>SWENSON,半周年振幅的大小顺序为:P3M6>P4M15>NONE>SWENSON。

Due to the influence of GRACE satellite orbit design and sensor errors,and background model errors during solution,the original time-varying gravitational field model solved by GRACE data contains obvious north-south banding errors.The results of inversion of land water reserves by different decorrelation methods are different,but there are relatively few comparative studies on different decorrelation methods in the Yangtze River Basin.The three different decorrelation methods SWENSON,P3M6,P4M15 are used to invert the Yangtze River Basin.Changes in land water reserves.Studies have shown that,in terms of spatial distribution,the spatial distribution of the P3M6 and P4M15 methods is relatively close,and the P4M15 signal loss is more.Although SWENSON retains more signals,its spatial distribution is quite different from the other two methods,which may be selected from empirical parameters.related.In the time series,the order of amplitude of the annual term of the change in land water reserves is P4M15>P3M6>NONE(without decorrelation processing)>SWENSON,and the order of amplitude of the half-annual amplitude is:P3M6>P4M15>NONE>SWENSON.