Introducing an Improved GRACE Global Point-Mass Solution—A Case Study in Antarctica.

Ferreira, Vagner G.; Yong, Bin; Seitz, Kurt; Heck, Bernhard; Grombein, Thomas (2020). Introducing an Improved GRACE Global Point-Mass Solution—A Case Study in Antarctica. Remote sensing, 12(19), p. 3197. Molecular Diversity Preservation International MDPI 10.3390/rs12193197

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In the so-called point-mass modeling, surface densities are represented by point masses, providing only an approximated solution of the surface integral for the gravitational potential. Here, we propose a refinement for the point-mass modeling based on Taylor series expansion in which the zeroth-order approximation is equivalent to the point-mass solution. Simulations show that adding higher-order terms neglected in the point-mass modeling reduces the error of inverted mass changes of up to 90% on global and Antarctica scales. The method provides an alternative to the processing of the Level-2 data from the Gravity Recovery and Climate Experiment (GRACE) mission. While the evaluation of the surface densities based on improved point-mass modeling using ITSG-Grace2018 Level-2 data as observations reveals noise level of approximately 5.77 mm, this figure is 5.02, 6.05, and 5.81 mm for Center for Space Research (CSR), Goddard Space Flight Center (GSFC), and Jet Propulsion Laboratory (JPL) mascon solutions, respectively. Statistical tests demonstrate that the four solutions are not significant different (95% confidence) over Antarctica Ice Sheet (AIS), despite the slight differences seen in the noises. Therefore, the estimated noise level for the four solutions indicates the quality of GRACE mass changes over AIS. Overall, AIS shows a mass loss of −7.58 mm/year during 2003–2015 based on the improved point-mass solution, which agrees with the values derived from mascon solutions.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Institute of Astronomy

UniBE Contributor:

Grombein, Thomas Maximilan

Subjects:

500 Science > 520 Astronomy

ISSN:

2072-4292

Publisher:

Molecular Diversity Preservation International MDPI

Language:

English

Submitter:

Pierre Fridez

Date Deposited:

17 Nov 2020 14:33

Last Modified:

17 Nov 2020 14:33

Publisher DOI:

10.3390/rs12193197

BORIS DOI:

10.7892/boris.147684

URI:

https://boris.unibe.ch/id/eprint/147684

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