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Can GPS and GRACE data be used to separate past and present-day surface loading in a data-driven approach?

Ziegler, Y and Vishwakarma, BD and Brady, A and Chuter, S and Royston, S and Westaway, RM and Bamber, JL (2023) Can GPS and GRACE data be used to separate past and present-day surface loading in a data-driven approach? In: Geophysical Journal International, 232 (2). pp. 884-901.

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Official URL: https://doi.org/10.1093/gji/ggac365


Glacial isostatic adjustment (GIA) and the hydrological cycle are both associated with mass changes and vertical land motion (VLM), which are observed by GRACE and GPS, respectively. Hydrology-related VLM results from the instantaneous response of the elastic solid Earth to surface loading by freshwater, whereas GIA-related VLM reveals the long-term response of the viscoelastic Earth mantle to past ice loading history. Thus, observations of mass changes and VLM are interrelated, making GIA and hydrology difficult to quantify and study independently. In this work, we investigate the feasibility of separating these processes based on GRACE and GPS observations, in a fully data-driven and physically consistent approach. We take advantage of the differences in the spatio-temporal characteristics of the GIA and hydrology fields to estimate the respective contributions of each component using a Bayesian hierarchical modelling framework. A closed-loop synthetic test confirms that our method successfully solves this source separation problem. However, there are significant challenges when applying the same approach with actual observations and the answer to the main question of this study is more nuanced. In particular, in regions where GPS station coverage is sparse, the lack of informative data becomes a limiting factor. © 2022 The Author(s). Published by Oxford University Press on behalf of The Royal Astronomical Society.

Item Type: Journal Article
Publication: Geophysical Journal International
Publisher: Oxford University Press
Additional Information: The copyright for this article belongs to the Authors.
Keywords: Geodesy; Geodetic satellites; Global positioning system; Source separation, Data-driven approach; Glacial Isostatic Adjustments; Joint inversion; Loading of the earth; Mass change; Past and present; Satellite geodesy; Surface loading; Time-variable gravity; Vertical land motions, Hydrology
Department/Centre: Division of Mechanical Sciences > Centre for Earth Sciences
Division of Interdisciplinary Sciences > Interdisciplinary Centre for Water Research
Date Deposited: 27 Jan 2023 08:39
Last Modified: 27 Jan 2023 08:39
URI: https://eprints.iisc.ac.in/id/eprint/79534

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