We carry out a comprehensive analysis and assessment of degree-2 gravitational changes ΔC₂₁, and ΔS₂₁, estimated using the Gravity Recovery and Climate Experiment (GRACE) and GRACE Follow-On (GFO), satellite laser ranging (SLR), Earth Orientation Parameters (EOP), and geophysical models over the period April 2002–February 2020. The four independent estimates of ΔC₂₁ and ΔS₂₁ variations agree well over a broad band of frequencies. The GRACE/GFO Release 6 (RL06) solutions show major improvements over the previous RL05 solutions at both seasonal and intra-seasonal time scales, when compared with EOP and SLR estimates. Among the four independent estimates, highest correlation coefficients and smallest RMS residuals are found between GRACE/GFO and EOP estimates of ΔC₂₁ and ΔS₂₁ variations. GRACE/GFO and EOP ΔC₂₁ and ΔS₂₁ estimates exhibit slightly different trends, which are related to the implementation and interpretation of the pole tide correction in GRACE/GFO data processing. This study provides an important early validation of GFO ΔC₂₁ and ΔS₂₁ solutions, especially the new pole tide correction applied in GRACE/GFO RL06 solutions using independent estimates.

我们进行了全面的分析和程度-2引力变化评估ΔC ₂₁，和ΔS ₂₁，利用重力恢复和气候实验（GRACE）和GRACE后续（GFO）估计，卫星激光测距（SLR），地球定向参数（EOP），以及地球物理模型在此期间2002年4月- 2020年二月四个ΔC的独立估算₂₁和ΔS ₂₁在很宽的频率范围内，变化都很好地吻合。与EOP和SLR估算值相比，GRACE / GFO第6版（RL06）解决方案在季节和季节内尺度上均显示出比以前RL05解决方案的重大改进。在四个独立估算，最高相关系数和最小的RMS残差GRACE / GFO和ΔC的EOP估计之间发现₂₁和ΔS _21种变化。GRACE / GFO和EOPΔC ₂₁和ΔS _21个预测图表稍有不同的趋势，这是有关在GRACE / GFO数据处理的执行和极潮更正的解释。这项研究提供GFOΔC的一个重要的早期验证₂₁和ΔS ₂₁ 解决方案，尤其是采用独立估计的GRACE / GFO RL06解决方案中应用的新的极潮修正。