GRACE / GRACE-FO¶

GRACE and GRACE Follow-On monthly terrestrial water storage (TWS) anomaly grids — JPL, CSR and GSFC mascons, JPL Tellus Level-3

Available

At a glance¶

Note on period: GRACE 2002-04 to 2017-06 (the last monthly solution spans 2017-05-23 to 06-29) and GRACE-FO 2018-06 to present, with nothing for 2017-07 to 2018-05. GRACE has no solutions for 2002-06/07, 2003-06, 2011-01/06, 2012-05/10, 2013-03/08/09, 2014-02/07/12, 2015-06/10/11, 2016-04/09/10 and 2017-02; GRACE-FO has none for 2018-08/09 (based on the JPL Tellus land grids). When checked on 2026-10-13, the latest months were 2026-07 for the JPL mascons, 2026-08 for the JPL Tellus land grids, 2026-08 for the CSR mascons (updated 2026-10-07) and 2026-03 for the GSFC mascons.

Overview¶

Gridded monthly changes in surface mass, expressed as equivalent water thickness, derived from month-to-month changes in Earth's gravity field measured through the distance between the twin satellites of GRACE (2002–2017) and its successor GRACE-FO (2018–). Over land they show changes in terrestrial water storage (TWS) — surface water, soil moisture, groundwater and snow combined — and are widely used for drought, groundwater depletion and ice sheet mass loss studies. There are mascon solutions (solved directly for regional mass concentrations) from JPL, CSR and GSFC, and JPL Tellus 1° land grids from filtered spherical harmonics; all values are anomalies relative to the 2004.0–2009.999 mean.

What changes with the successor¶

GRACE → GRACE-FO¶

Transition: 2018-06

GRACE ended science operations in October 2017, and GRACE-FO, which continues the same design, launched on 22 May 2018 and resumed the record from June 2018. There is a gap of about 11 months (2017-07 to 2018-05) between the missions, but the GRACE-FO team reported no biases across the gap and precision on a par with GRACE.

Sources: Landerer et al. (2020) GRACE-FO instrument and science data performance, GRL · JPL News — Prolific Earth Gravity Satellites End Science Mission (2017-10-27) · GRACE-FO Level-3 Data Product User Handbook (JPL) · NASA — GRACE-FO Satellite Switching to Backup Instrument Processing Unit (2018-09-17)

GRACE / GRACE-FO RL06.x → RL07 Planned¶

Transition: 2026

The full GRACE and GRACE-FO record is being reprocessed to new standards (Release 07). GRACE Level-2 RL07 (CSR and JPL) was published at PO.DAAC on 2026-05-01, but when checked on 2026-10-13 there were no public collections yet for GRACE-FO RL07 or for the Tellus Level-3 and mascon RL07 products. CMR does, however, already hold variable records for the JPL mascon RL07 (TELLUS_GRAC-GRFO_MASCON_CRI_GRID_RL07_v01) dated 2026-07-17, which suggests a release is being prepared.

Sources: NASA CMR — GRACE Level-2 JPL RL07 (GRACE_L2_JPL_MONTHLY_0070) · Level-2 Status from JPL (GRACE-FO Science Team Meeting, 2025-10-07) · GRACE-FO project status (2025-10)

GRACE-FO → GRACE-C Planned¶

Transition: 2028-12

The NASA–DLR follow-on mission GRACE-C (GRACE-Continuity) is in development for a Falcon 9 launch targeted for December 2028 (it passed its System Integration Review in October 2025). The plan is to extend GRACE-FO operations into 2029 to overlap for about a year for cross-calibration.

Sources: GFZ — GRACE-C · GRACE-C status (Landerer, 2025-10) · EGU26-16387 — GRACE-FO extended mission phase and GRACE-C developments

Available variables¶

Variable names in the JPL mascon (RL06.3Mv04) and JPL Tellus Level-3 (RL06 v04, RL06.3 v04) files, as listed in the PO.DAAC collection information. The CSR and GSFC mascons are organised differently (CSR NetCDF; GSFC HDF5, ASCII and NetCDF), so see their own pages.

instantaneous mean accumulated maximum minimum static — instantaneous: value at the time stamp · mean/accumulated/maximum/minimum: over the indicated interval · static: does not change with time

JPL mascons (RL06.3Mv04, CRI-filtered and unfiltered versions)¶

JPL Tellus Level-3 land grids (1°, GRACE RL06 v04 / GRACE-FO RL06.3 v04)¶

Fixed fields¶

The full variable list is in the official documentation.

How to get the data¶

• PO.DAAC (NASA Earthdata Cloud) — JPL mascon CRI RL06.3Mv04 — HTTPS / earthaccess / OPeNDAP / AWS S3 (us-west-2) — Earthdata Login required
  • A single NetCDF file from 2002 to the latest month (e.g. GRCTellus.JPL.200204_202607.GLO.RL06.3M.MSCNv04CRI.nc). It is replaced by a new file every month, so download again for the newest month. The unfiltered version is TELLUS_GRAC-GRFO_MASCON_GRID_RL06.3_V4. The podaac-data-subscriber tool is also recommended for bulk downloads.
• PO.DAAC — JPL, CSR and GFZ Tellus Level-3 land grids — HTTPS / earthaccess — Earthdata Login required
  • Split into GRACE collections TELLUS_GRAC_L3_{JPL,CSR,GFZ}RL06_LND_v04 and GRACE-FO collections TELLUS_GRFO_L3_RL06.3_LND_v04, one file per month. Ocean bottom pressure grids (OCN) are separate collections.
• CSR GRACE/GRACE-FO RL06.3 mascons (UT Austin) — Direct HTTPS download (no account)
  • One file, CSR_GRACE_GRACE-FO_RL0603_Mascons_all-corrections.nc (0.25°), plus land and ocean masks and grids of each correction component. Updated 2026-10-07, through 2026-08.
• NASA GSFC mascons (RL06v2.0) — Direct HTTPS download (HDF5, ASCII, NetCDF)
  • 2002-04 to 2026-03 as of the 2026-09-30 page update. A 0.5° NetCDF version is also available.
• JPL GRACE Tellus website (data guides and news) — Web guides / visualisation
  • Data release news is posted at https://grace.jpl.nasa.gov/data/data-updates/.

Example code¶

Downloads the JPL mascon CRI RL06.3Mv04 file with earthaccess and builds a terrestrial water storage anomaly series for the North China Plain (113–120°E, 34–40°N). The first run asks for Earthdata credentials. Longitudes are 0–360°; for land hydrology, multiply by the gain factor (scale_factor) and then take an area-weighted (cos latitude) mean.

import earthaccess
import numpy as np
import xarray as xr

earthaccess.login()  # free NASA Earthdata account
results = earthaccess.search_data(
    short_name="TELLUS_GRAC-GRFO_MASCON_CRI_GRID_RL06.3_V4",
    version="RL06.3Mv04",
)
files = earthaccess.download(results, "grace_mascon")   # the whole record since 2002 is one file

ds = xr.open_dataset(files[0])
tws = ds["lwe_thickness"] * ds["scale_factor"]           # cm, relative to 2004.0-2009.999 mean
tws = tws.where(ds["land_mask"] == 1)
box = tws.sel(lat=slice(34, 40), lon=slice(113, 120))
w = np.cos(np.deg2rad(box.lat))
series = box.weighted(w).mean(["lat", "lon"])
print(series.to_series().tail())                         # missing months have no time step at all

Practical tips¶

• All values are anomalies relative to the 2004.0–2009.999 mean. They are not absolute storage; when comparing with other data, subtract a common baseline again.
• Missing months (20 GRACE months, GRACE-FO 2018-08 and 2018-09) and the 2017-07 to 2018-05 gap have no time steps in the files. Code that assumes a regular monthly sequence (e.g. grouping every 12 steps into a year) will give wrong results.
• The real resolution of the JPL mascons is the 3° mascon (about 300 km). Do not read a single 0.5° cell as a point value; use averages over sufficiently large basins.
• The gain factor (scale_factor) is for land hydrology. Do not apply it to ice sheets or oceans. JPL notes that the CLM4 gain factors for the Tellus 1° land grids are dominated by annual cycles and may not suit trend analysis.
• For the Tellus 1° land grids (from spherical harmonics), JPL recommends averaging the JPL, CSR and GFZ solutions, and advises using mascons for Greenland, Antarctica and glacier mass studies.
• The late-GRACE 'accelerometer transplant' months (2016-11, 2016-12, 2017-01, 2017-03, 2017-04, 2017-06) are noisier. GRACE-FO also replaces the GF2 accelerometer with data derived from GF1, and values for January–February 2023 and from July 2023 onward (wide-deadband pointing) changed between RL06.1 and RL06.3.
• September–November 2024 has lower quality because of poor repeat-orbit sampling, and similar degradation was expected from July 2026 to February 2027. Check whether abrupt changes in these periods are real signals.
• The JPL, CSR and GSFC mascons differ in regularisation, grid and corrections (e.g. when C30 replacement starts), so the same month gives different values. Compare several solutions to gauge uncertainty, but do not mix them within one time series.

Notices and change history¶

References for your paper¶

Dataset citation¶

JPL mascon CRI RL06.3Mv04 (PO.DAAC) — DOI 10.5067/TEMSC-3JC634

@misc{wiese2023jplmascon_cri,
  author    = {Wiese, D. N. and Yuan, D.-N. and Boening, C. and Landerer, F. W. and Watkins, M. M.},
  title     = {{JPL} {GRACE} and {GRACE-FO} Mascon Ocean, Ice, and Hydrology Equivalent Water Height {CRI} Filtered {RL06.3Mv04}},
  version   = {RL06.3Mv04},
  publisher = {PO.DAAC},
  address   = {CA, USA},
  year      = {2023},
  doi       = {10.5067/TEMSC-3JC634}
}

JPL mascon (no CRI filter) RL06.3Mv04 (PO.DAAC) — DOI 10.5067/TEMSC-3MJ634

@misc{wiese2023jplmascon,
  author    = {Wiese, D. N. and Yuan, D.-N. and Boening, C. and Landerer, F. W. and Watkins, M. M.},
  title     = {{JPL} {GRACE} and {GRACE-FO} Mascon Ocean, Ice, and Hydrology Equivalent Water Height {JPL} {RL06.3Mv04}},
  version   = {RL06.3Mv04},
  publisher = {PO.DAAC},
  address   = {CA, USA},
  year      = {2023},
  doi       = {10.5067/TEMSC-3MJ634}
}

JPL Tellus GRACE-FO Level-3 land grids RL06.3 v04 (PO.DAAC) — DOI 10.5067/GFLND-3J634

@misc{landerer2023tellus_grfo_jpl,
  author    = {Landerer, Felix},
  title     = {{JPL} {TELLUS} {GRACE-FO} Level-3 Monthly Land Water-Equivalent-Thickness Surface Mass Anomaly Release 6.3 version 04},
  version   = {RL06.3v04},
  publisher = {PO.DAAC},
  address   = {CA, USA},
  year      = {2023},
  doi       = {10.5067/GFLND-3J634}
}

JPL Tellus GRACE Level-3 land grids RL06 v04 (PO.DAAC) — DOI 10.5067/TELND-3AJ64

@misc{landerer2021tellus_grac_jpl,
  author    = {Landerer, Felix},
  title     = {{TELLUS\_GRAC\_L3\_JPL\_RL06\_LND\_v04}},
  version   = {RL06 v04},
  publisher = {PO.DAAC},
  address   = {CA, USA},
  year      = {2021},
  doi       = {10.5067/TELND-3AJ64}
}

CSR GRACE/GRACE-FO mascons (UT Austin CSR) — DOI 10.15781/cgq9-nh24

@misc{save2020csrmascon,
  author = {Save, Himanshu},
  title  = {{CSR} {GRACE} and {GRACE-FO} {RL06} Mascon Solutions v02},
  year   = {2020},
  doi    = {10.15781/cgq9-nh24}
}

Reference papers¶

JPL mascon method — DOI 10.1002/2014JB011547

@article{watkins2015mascons,
  author  = {Watkins, Michael M. and Wiese, David N. and Yuan, Dah-Ning and Boening, Carmen and Landerer, Felix W.},
  title   = {Improved methods for observing {Earth}'s time variable mass distribution with {GRACE} using spherical cap mascons},
  journal = {Journal of Geophysical Research: Solid Earth},
  volume  = {120},
  number  = {4},
  pages   = {2648--2671},
  year    = {2015},
  doi     = {10.1002/2014JB011547}
}

CRI filter and leakage errors (JPL mascons) — DOI 10.1002/2016WR019344

@article{wiese2016leakage,
  author  = {Wiese, David N. and Landerer, Felix W. and Watkins, Michael M.},
  title   = {Quantifying and reducing leakage errors in the {JPL} {RL05M} {GRACE} mascon solution},
  journal = {Water Resources Research},
  volume  = {52},
  number  = {9},
  pages   = {7490--7502},
  year    = {2016},
  doi     = {10.1002/2016WR019344}
}

CSR mascon method — DOI 10.1002/2016JB013007

@article{save2016csr,
  author  = {Save, Himanshu and Bettadpur, Srinivas and Tapley, Byron D.},
  title   = {High-resolution {CSR} {GRACE} {RL05} mascons},
  journal = {Journal of Geophysical Research: Solid Earth},
  volume  = {121},
  number  = {10},
  pages   = {7547--7569},
  year    = {2016},
  doi     = {10.1002/2016JB013007}
}

GSFC mascon method — DOI 10.1007/s00190-019-01252-y

@article{loomis2019gsfc,
  author  = {Loomis, B. D. and Luthcke, S. B. and Sabaka, T. J.},
  title   = {Regularization and error characterization of {GRACE} mascons},
  journal = {Journal of Geodesy},
  volume  = {93},
  number  = {9},
  pages   = {1381--1398},
  year    = {2019},
  doi     = {10.1007/s00190-019-01252-y}
}

Gain factors for the Tellus land grids — DOI 10.1029/2011WR011453

@article{landerer2012scaled,
  author  = {Landerer, F. W. and Swenson, S. C.},
  title   = {Accuracy of scaled {GRACE} terrestrial water storage estimates},
  journal = {Water Resources Research},
  volume  = {48},
  number  = {4},
  pages   = {W04531},
  year    = {2012},
  doi     = {10.1029/2011WR011453}
}

GRACE-FO performance and continuity of the GRACE record — DOI 10.1029/2020GL088306

@article{landerer2020gracefo,
  author  = {Landerer, Felix W. and Flechtner, Frank M. and Save, Himanshu and Webb, Frank H. and Bandikova, Tamara and Bertiger, William I. and Bettadpur, Srinivas V. and Byun, Sung Hun and Dahle, Christoph and Dobslaw, Henryk and Fahnestock, Eugene and Harvey, Nate and Kang, Zhigui and Kruizinga, Gerhard L. H. and Loomis, Bryant D. and McCullough, Christopher and Murb{\"o}ck, Michael and Nagel, Peter and Paik, Meegyeong and Pie, Nadege and Poole, Steve and Strekalov, Dmitry and Tamisiea, Mark E. and Wang, Furun and Watkins, Michael M. and Wen, Hui-Ying and Wiese, David N. and Yuan, Dah-Ning},
  title   = {Extending the Global Mass Change Data Record: {GRACE} Follow-On Instrument and Science Data Performance},
  journal = {Geophysical Research Letters},
  volume  = {47},
  number  = {12},
  pages   = {e2020GL088306},
  year    = {2020},
  doi     = {10.1029/2020GL088306}
}

Acknowledgements¶

Cite the dataset DOI of each product used, together with Watkins et al. (2015) and Wiese et al. (2016) for the JPL mascons, Save et al. (2016) for the CSR mascons, Loomis et al. (2019) for the GSFC mascons and Landerer and Swenson (2012) for the Tellus land grids. CSR asks users to acknowledge that the data were downloaded from the CSR GRACE website.

Information on the datasets used in this study was compiled with the help of the Korean Climate Data Navigator (KCDN) (Sim, 2026; https://doi.org/10.5281/zenodo.23300923).

Links¶

• JPL GRACE Tellus — mascon guide
• JPL GRACE Tellus — data updates
• JPL GRACE Tellus — land grids (spherical harmonics) guide
• GRACE/GRACE-FO months and missing days
• GRACE-FO Level-3 Data Product User Handbook (JPL)
• JPL mascon release notes (including RL06.3Mv04)
• GRACE documents and technical notes (PO.DAAC)
• CSR RL06.3 mascons
• NASA GSFC mascons
• GFZ — GRACE-C
• This site — ITS_LIVE glacier and ice-sheet velocity