利用2003-01～2016-06共162个月GLDAS_NOAH_M.2.1、GLDAS_NOAH_M.001新旧水文模型和GRACE卫星重力数据,计算青藏高原区域水储量及总质量变化,说明GLDAS_NOAH_M.2.1水文模型相对于旧模型可提升在青藏高原区域的精度.将研究区域分为6个部分,根据3种数据分别计算6个区域的平均质量变化时间序列,顾及年周期、半年周期对该时间序列进行最小二乘拟合,估计6个区域3种数据的年振幅、年相位及相关性.结果表明,GLDAS_ NOAH_M.2.1水储量变化的年振幅、年相位与GRACE总质量变化的年振幅、年相位空间分布大体一致,在青藏高原北部区域与GRACE的相关性尤为明显;GLDAS_NOAH_M.001年振幅、年相位在青藏高原北部区域存在明显异常,与GRACE的相关性很低.从长趋势质量变化来看,GLDAS新、旧模型在不同区域的差异为—6.4～4.5 Gt/a量级,而在青藏高原主体区域,新模型的质量趋势偏低10.4 Gt/a.%A new GLDAS_NOAH_M.2.1 land water model and its old version of GLDAS_NOAH_M.001 from January 2003 and June 2016,totally 162 months,are investigated here with GRACE satellite gravimetry observations to study soil moisture and total mass change in the Qinghai-Tibet plateau.Our result shows that GLDAS_NOAH_M.2.1 has an improved precision in simulating soil moisture change.Here,6 study regions are divided and in each region these three data sets are used to estimate mass changes,whose correlation coefficient and periodic terms are derived.Compared with GLDAS_ NOAH_M.001,GLDAS_NOAH_M.2.1 has a better performance in correlation with GRACE in terms of periodic variations.The correlation between GLDAS_NOAH_M.001 and GRACE is very poor in northern Tibet,while GLDAS_NOAH_M.2.1 has improved this condition.In terms of secular mass change,GLDAS_NOAH_M.2.1 brings a difference at the order of —6.4～4.5 Gt/a in different regions and a total different of —10.4 Gt/a in the main part of Qinghai-Tibet plateau.
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