Constrained Linear Deconvolution of GRACE Anomalies to Correct Spatial Leakage
Open Access
- 2 June 2020
- journal article
- letter
- Published by MDPI AG in Remote Sensing
- Vol. 12 (11), 1798
- https://doi.org/10.3390/rs12111798
Abstract
Time-varying gravity observed by the Gravity Recovery and Climate Experiment (GRACE) satellites measures surface water and ice mass redistribution driven by weather and climate forcing and has emerged as one of the most important data types in measuring changes in Earth’s climate. However, spatial leakage of GRACE signals, especially in coastal areas, has been a recognized limitation in quantitatively assessing mass change. It is evident that larger terrestrial signals in coastal regions spread into the oceans and vice versa and various remedies have been developed to address this problem. An especially successful one has been Forward Modeling but it requires knowledge of geographical locations of mass change to be fully effective. In this study, we develop a new method to suppress leakage effects using a linear least squares operator applied to GRACE spherical harmonic data. The method is effectively a constrained deconvolution of smoothing inherent in GRACE data. It assumes that oceanic mass changes near the coast are negligible compared to terrestrial changes, with additional spatial regularization constraints. Some calibration of constraint weighting is required. We apply the method to estimate surface mass loads over Australia using both synthetic and real GRACE data. Leakage into the oceans is effectively suppressed and when compared with mascon solutions there is better performance over interior basins.Funding Information
- Korea Institute of Marine Science and Technology promotion (KIMST20190361;PM19020)
- National Research Foundation of Korea (NO. 2020R1A2C2006857, NO. 2018R1C1B5086283)
- Nuclear Safety and Security Commission (No. 1705010)
This publication has 23 references indexed in Scilit:
- Antarctica, Greenland and Gulf of Alaska land-ice evolution from an iterated GRACE global mascon solutionJournal of Glaciology, 2013
- Interannual variability of Greenland ice losses from satellite gravimetryJournal of Geophysical Research, 2011
- Closure of the budget of global sea level rise over the GRACE era: the importance and magnitudes of the required corrections for global glacial isostatic adjustmentQuaternary Science Reviews, 2009
- GRACE's spatial aliasing errorGeophysical Journal International, 2008
- Post‐processing removal of correlated errors in GRACE dataGeophysical Research Letters, 2006
- Simulated estimation of hydrological loads from GRACEJournal of Geodesy, 2005
- Static and temporal gravity field recovery using grace potential difference observablesAdvances in Geosciences, 2003
- Time variability of the Earth's gravity field: Hydrological and oceanic effects and their possible detection using GRACEJournal of Geophysical Research, 1998
- Occam’s inversion: A practical algorithm for generating smooth models from electromagnetic sounding dataGeophysics, 1987
- A REVIEW OF LEAST‐SQUARES INVERSION AND ITS APPLICATION TO GEOPHYSICAL PROBLEMS*Geophysical Prospecting, 1984