Reproducing GRACE Total Water Storage Change at Finer Spatial Scales. Li, F. & Kusche, J. Geophysical Research Letters, 53(1):e2025GL119881, January, 2026. ![Reproducing GRACE Total Water Storage Change at Finer Spatial Scales [link]](https://bibbase.org/img/filetypes/link.svg "link")
Paper doi abstract bibtex Abstract The Gravity Recovery and Climate Experiment (GRACE) satellite mission provides accurate observations of terrestrial water storage anomalies (TWSA), but their coarse spatial resolution (∼3°) limits sub‐regional‐scale applications. Existing downscaling methods rely on high‐resolution hydrometeorological inputs, which often underestimate the full magnitude of GRACE signals. Here, we develop a machine‐learning‐based iterative downscaling method that reproduces TWSA at 0.25° resolution while retaining nearly all of the original GRACE signals, using ERA5 soil moisture, precipitation, and temperature as inputs. We find that the downscaled TWSA has improved agreement with in situ groundwater levels compared to the original GRACE data, with higher correlation at over 63% of wells and reduced RMSE at more than 83% globally. The downscaled TWSA also retains an average correlation of 0.99 with original GRACE data at the basin scale, outperforming a previously released downscaling product. The downscaled TWSA data set is publicly available at https://doi.org/10.5281/zenodo.17265162 . , Plain Language Summary The Gravity Recovery and Climate Experiment (GRACE) satellite mission helps scientists monitor changes in water stored underground, in soil, and on the surface across the globe. However, GRACE data has a low resolution, making it hard to study smaller regions. Existing methods to improve this resolution often miss important signals, especially those caused by human activity. In this study, we created a new method to increase the resolution of GRACE data while keeping most of the original information. We tested our results using groundwater data from nearly 27,000 wells worldwide and found that our improved data matched local measurements much better than the original. It may outperform other existing methods, based on a comparison with a previously released downscaling product. Our high‐resolution groundwater data is freely available to the public at: https://doi.org/10.5281/zenodo.17265162 . , Key Points We develop an iterative downscaling method that reproduces GRACE total water storage anomalies (TWSA) at 0.25° spatial resolution Downscaled TWSA better fits global groundwater observations from 26,881 wells compared to the original GRACE data Downscaled TWSA shows better consistency than a released product with both original GRACE data and in situ groundwater observations
@article{li_reproducing_2026,
title = {Reproducing {GRACE} {Total} {Water} {Storage} {Change} at {Finer} {Spatial} {Scales}},
volume = {53},
issn = {0094-8276, 1944-8007},
url = {https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2025GL119881},
doi = {10.1029/2025GL119881},
abstract = {Abstract
The Gravity Recovery and Climate Experiment (GRACE) satellite mission provides accurate observations of terrestrial water storage anomalies (TWSA), but their coarse spatial resolution (∼3°) limits sub‐regional‐scale applications. Existing downscaling methods rely on high‐resolution hydrometeorological inputs, which often underestimate the full magnitude of GRACE signals. Here, we develop a machine‐learning‐based iterative downscaling method that reproduces TWSA at 0.25° resolution while retaining nearly all of the original GRACE signals, using ERA5 soil moisture, precipitation, and temperature as inputs. We find that the downscaled TWSA has improved agreement with in situ groundwater levels compared to the original GRACE data, with higher correlation at over 63\% of wells and reduced RMSE at more than 83\% globally. The downscaled TWSA also retains an average correlation of 0.99 with original GRACE data at the basin scale, outperforming a previously released downscaling product. The downscaled TWSA data set is publicly available at
https://doi.org/10.5281/zenodo.17265162
.
,
Plain Language Summary
The Gravity Recovery and Climate Experiment (GRACE) satellite mission helps scientists monitor changes in water stored underground, in soil, and on the surface across the globe. However, GRACE data has a low resolution, making it hard to study smaller regions. Existing methods to improve this resolution often miss important signals, especially those caused by human activity. In this study, we created a new method to increase the resolution of GRACE data while keeping most of the original information. We tested our results using groundwater data from nearly 27,000 wells worldwide and found that our improved data matched local measurements much better than the original. It may outperform other existing methods, based on a comparison with a previously released downscaling product. Our high‐resolution groundwater data is freely available to the public at:
https://doi.org/10.5281/zenodo.17265162
.
,
Key Points
We develop an iterative downscaling method that reproduces GRACE total water storage anomalies (TWSA) at 0.25° spatial resolution
Downscaled TWSA better fits global groundwater observations from 26,881 wells compared to the original GRACE data
Downscaled TWSA shows better consistency than a released product with both original GRACE data and in situ groundwater observations},
language = {en},
number = {1},
urldate = {2026-01-13},
journal = {Geophysical Research Letters},
author = {Li, Fupeng and Kusche, Jürgen},
month = jan,
year = {2026},
pages = {e2025GL119881},
}
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Here, we develop a machine‐learning‐based iterative downscaling method that reproduces TWSA at 0.25° resolution while retaining nearly all of the original GRACE signals, using ERA5 soil moisture, precipitation, and temperature as inputs. We find that the downscaled TWSA has improved agreement with in situ groundwater levels compared to the original GRACE data, with higher correlation at over 63% of wells and reduced RMSE at more than 83% globally. The downscaled TWSA also retains an average correlation of 0.99 with original GRACE data at the basin scale, outperforming a previously released downscaling product. The downscaled TWSA data set is publicly available at https://doi.org/10.5281/zenodo.17265162 . , Plain Language Summary The Gravity Recovery and Climate Experiment (GRACE) satellite mission helps scientists monitor changes in water stored underground, in soil, and on the surface across the globe. However, GRACE data has a low resolution, making it hard to study smaller regions. Existing methods to improve this resolution often miss important signals, especially those caused by human activity. In this study, we created a new method to increase the resolution of GRACE data while keeping most of the original information. We tested our results using groundwater data from nearly 27,000 wells worldwide and found that our improved data matched local measurements much better than the original. It may outperform other existing methods, based on a comparison with a previously released downscaling product. Our high‐resolution groundwater data is freely available to the public at: https://doi.org/10.5281/zenodo.17265162 . , Key Points We develop an iterative downscaling method that reproduces GRACE total water storage anomalies (TWSA) at 0.25° spatial resolution Downscaled TWSA better fits global groundwater observations from 26,881 wells compared to the original GRACE data Downscaled TWSA shows better consistency than a released product with both original GRACE data and in situ groundwater observations","language":"en","number":"1","urldate":"2026-01-13","journal":"Geophysical Research Letters","author":[{"propositions":[],"lastnames":["Li"],"firstnames":["Fupeng"],"suffixes":[]},{"propositions":[],"lastnames":["Kusche"],"firstnames":["Jürgen"],"suffixes":[]}],"month":"January","year":"2026","pages":"e2025GL119881","bibtex":"@article{li_reproducing_2026,\n\ttitle = {Reproducing {GRACE} {Total} {Water} {Storage} {Change} at {Finer} {Spatial} {Scales}},\n\tvolume = {53},\n\tissn = {0094-8276, 1944-8007},\n\turl = {https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2025GL119881},\n\tdoi = {10.1029/2025GL119881},\n\tabstract = {Abstract\n \n The Gravity Recovery and Climate Experiment (GRACE) satellite mission provides accurate observations of terrestrial water storage anomalies (TWSA), but their coarse spatial resolution (∼3°) limits sub‐regional‐scale applications. Existing downscaling methods rely on high‐resolution hydrometeorological inputs, which often underestimate the full magnitude of GRACE signals. Here, we develop a machine‐learning‐based iterative downscaling method that reproduces TWSA at 0.25° resolution while retaining nearly all of the original GRACE signals, using ERA5 soil moisture, precipitation, and temperature as inputs. We find that the downscaled TWSA has improved agreement with in situ groundwater levels compared to the original GRACE data, with higher correlation at over 63\\% of wells and reduced RMSE at more than 83\\% globally. The downscaled TWSA also retains an average correlation of 0.99 with original GRACE data at the basin scale, outperforming a previously released downscaling product. The downscaled TWSA data set is publicly available at\n https://doi.org/10.5281/zenodo.17265162\n .\n \n , \n Plain Language Summary\n \n The Gravity Recovery and Climate Experiment (GRACE) satellite mission helps scientists monitor changes in water stored underground, in soil, and on the surface across the globe. However, GRACE data has a low resolution, making it hard to study smaller regions. Existing methods to improve this resolution often miss important signals, especially those caused by human activity. In this study, we created a new method to increase the resolution of GRACE data while keeping most of the original information. We tested our results using groundwater data from nearly 27,000 wells worldwide and found that our improved data matched local measurements much better than the original. It may outperform other existing methods, based on a comparison with a previously released downscaling product. Our high‐resolution groundwater data is freely available to the public at:\n https://doi.org/10.5281/zenodo.17265162\n .\n \n , \n Key Points\n \n \n \n We develop an iterative downscaling method that reproduces GRACE total water storage anomalies (TWSA) at 0.25° spatial resolution\n \n \n Downscaled TWSA better fits global groundwater observations from 26,881 wells compared to the original GRACE data\n \n \n Downscaled TWSA shows better consistency than a released product with both original GRACE data and in situ groundwater observations},\n\tlanguage = {en},\n\tnumber = {1},\n\turldate = {2026-01-13},\n\tjournal = {Geophysical Research Letters},\n\tauthor = {Li, Fupeng and Kusche, Jürgen},\n\tmonth = jan,\n\tyear = {2026},\n\tpages = {e2025GL119881},\n}\n\n\n\n","author_short":["Li, F.","Kusche, J."],"key":"li_reproducing_2026","id":"li_reproducing_2026","bibbaseid":"li-kusche-reproducinggracetotalwaterstoragechangeatfinerspatialscales-2026","role":"author","urls":{"Paper":"https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2025GL119881"},"metadata":{"authorlinks":{}}},"bibtype":"article","biburl":"https://bibbase.org/zotero/kasicamper","dataSources":["cTPSncuTZKDCfprGZ"],"keywords":[],"search_terms":["reproducing","grace","total","water","storage","change","finer","spatial","scales","li","kusche"],"title":"Reproducing GRACE Total Water Storage Change at Finer Spatial Scales","year":2026}