A Multi‐Source GRACE Fusion Solution via Uncertainty Quantification of GRACE‐Derived Terrestrial Water Storage (TWS) Change.
In: Journal of Geophysical Research. Solid Earth, Jg. 128 (2023-11-01), Heft 11, S. 1-25
Online
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Zugriff:
In analyzing terrestrial water storage (TWS) data observed by Gravity Recovery and Climate Experiment (GRACE) and GRACE Follow‐On satellites, quantifying uncertainties proves challenging due to the scarcity of sufficient independent observations of mass changes at scales commensurate with these missions. Moreover, owing to the diverse geophysical background models and processing techniques utilized by data processing centers, reaching consistent mass change estimations within specific regions of published solutions often proves arduous. We, therefore, quantified the uncertainty of the GRACE‐derived TWS changes by using the generalized three‐cornered hat method without relying on any prior knowledge and fused it to generate a higher‐quality solution. The findings reveal that of the six solutions, the Center for Space Research spherical harmonics (SH) solution exhibits the lowest uncertainty and highest signal‐to‐noise ratio (SNR) at both global and basin scales, and the Goddard Space Flight Center Mascon solution outperforms other Mascon counterparts. The fusion solution has an average 36.56% reduction in uncertainty and a 1.92‐fold improvement in SNR at the basin scale, and the improvement in SNR is particularly significant in regions with drastic mass changes. The global distribution patterns of the uncertainties associated with Mascon and SH solutions exhibit distinct differences. Mascon solutions result in significant signal leakage around regions characterized by the most substantial global mass variability. Additionally, transient mass changes triggered by super earthquake events in the ocean also produce similar "scars" in the global spatial distribution of uncertainties. The analysis of 142 basins worldwide shows that basins with more significant TWS annual oscillations have larger uncertainties but also better SNR. Plain Language Summary: Gravity Recovery and Climate Experiment (GRACE) and its successor, GRACE Follow‐On have furnished direct estimates of total water storage from the surface to the groundwater, providing invaluable benefits for studying the continental water cycle and quantifying water resources on a global scale. However, uncertainties in GRACE observations are difficult to assess, and there is some inconsistency in the mass variation obtained in some regions for solutions published by different institutions. In this work, we quantified the uncertainty in over 19 years of GRACE and GRACE Follow‐On (GRACE‐FO) solutions published by several major GRACE data processing centers and found significant differences in the global distribution patterns of uncertainty for different types of solutions. A more highly accurate fusion solution was subsequently generated based on this. The fused solution resulted in improved effectiveness of GRACE data, especially in regions with drastic mass changes. A reference and benchmark for the selection and use of GRACE products in future studies can be provided by this fusion solution. Key Points: Global spatial discrepancies in uncertainty and signal‐to‐noise ratio (SNR) are markedly pronounced between Gravity Recovery and Climate Experiment (GRACE) spherical harmonics and MasconsBasins exhibiting larger annual oscillations in terrestrial water storage have larger uncertainties but also superior SNRsThe fusion GRACE solution exhibits outstanding performance, enhancing the SNR by 1.92× across 142 basins globally [ABSTRACT FROM AUTHOR]
Titel: |
A Multi‐Source GRACE Fusion Solution via Uncertainty Quantification of GRACE‐Derived Terrestrial Water Storage (TWS) Change.
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Autor/in / Beteiligte Person: | Gao, Shengjun ; Hao, Weifeng ; Fan, Yi ; Li, Fei ; Wang, Jing |
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Zeitschrift: | Journal of Geophysical Research. Solid Earth, Jg. 128 (2023-11-01), Heft 11, S. 1-25 |
Veröffentlichung: | 2023 |
Medientyp: | academicJournal |
ISSN: | 2169-9313 (print) |
DOI: | 10.1029/2023JB026908 |
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