Improved Estimates of Geocenter Variability from Time-Variable Gravity and Ocean Model Outputs

Remote Sensing

卷:11

Isabella Velicogna¹  TylerC. Sutterley² 

[1] Department of Earth System Science, University of California, Irvine, CA 92697, USA;

[2] NASA Goddard Space Flight Center, Cryospheric Sciences Laboratory, Greenbelt, MD 20771, USA;

关键词: GRACE;    GRACE-FO;    time-variable gravity;    geocenter;    reference frames;    self-attraction and loading;   

DOI  :  10.3390/rs11182108

来源: DOAJ

【 摘 要 】

Geocenter variations relate the motion of the Earth’s center of mass with respect to its center of figure, and represent global-scale redistributions of the Earth’s mass. We investigate different techniques for estimating of geocenter motion from combinations of time-variable gravity measurements from the Gravity Recovery and Climate Experiment (GRACE) and GRACE Follow-On missions, and bottom pressure outputs from ocean models. Here, we provide self-consistent estimates of geocenter variability incorporating the effects of self-attraction and loading, and investigate the effect of uncertainties in atmospheric and oceanic variation. The effects of self-attraction and loading from changes in land water storage and ice mass change affect both the seasonality and long-term trend in geocenter position. Omitting the redistribution of sea level affects the average annual amplitudes of the x, y, and z components by 0.2, 0.1, and 0.3 mm, respectively, and affects geocenter trend estimates by 0.02, 0.04 and 0.05 mm/yr for the the x, y, and z components, respectively. Geocenter estimates from the GRACE Follow-On mission are consistent with estimates from the original GRACE mission.

【 授权许可】

Unknown