Geophysical Journal International Geophys. J. Int. (2015) 203, 1773–1786 doi: 10.1093/gji/ggv392 GJI Gravity, geodesy and tides GRACE time-variable gravity field recovery using an improved energy balance approach Kun Shang,1 Junyi Guo,1 C.K. Shum,1,2 Chunli Dai1 and Jia Luo3 1Division of Geodetic Science, School of Earth Sciences, The Ohio State University, 125 S. Oval Mall, Columbus, OH 43210, USA. E-mail:
[email protected] 2Institute of Geodesy & Geophysics, Chinese Academy of Sciences, Wuhan, China 3School of Geodesy and Geomatics, Wuhan University, 129 Luoyu Road, Wuhan 430079, China Accepted 2015 September 14. Received 2015 September 12; in original form 2015 March 19 Downloaded from SUMMARY A new approach based on energy conservation principle for satellite gravimetry mission has been developed and yields more accurate estimation of in situ geopotential difference observ- ables using K-band ranging (KBR) measurements from the Gravity Recovery and Climate Experiment (GRACE) twin-satellite mission. This new approach preserves more gravity in- http://gji.oxfordjournals.org/ formation sensed by KBR range-rate measurements and reduces orbit error as compared to previous energy balance methods. Results from analysis of 11 yr of GRACE data indicated that the resulting geopotential difference estimates agree well with predicted values from of- ficial Level 2 solutions: with much higher correlation at 0.9, as compared to 0.5–0.8 reported by previous published energy balance studies. We demonstrate that our approach produced a comparable time-variable gravity solution with the Level 2 solutions. The regional GRACE temporal gravity solutions over Greenland reveals that a substantially higher temporal resolu- at Ohio State University Libraries on December 20, 2016 tion is achievable at 10-d sampling as compared to the official monthly solutions, but without the compromise of spatial resolution, nor the need to use regularization or post-processing.