GRACE Monthly Mass Grids - Ocean

NASA/GRACE/MASS_GRIDS/OCEAN
Dataset Availability
2002-07-31T00:00:00 - 2017-01-05T00:00:00
Dataset Provider
Earth Engine Snippet
ee.ImageCollection("NASA/GRACE/MASS_GRIDS/OCEAN")
Tags
grace tellus gravity mass water ocean nasa jpl crs gfz

Description

GRACE Tellus Monthly Mass Grids provides monthly gravitational anomalies relative to a 2004-2010 time-mean baseline. The data contained in this dataset are units of "Equivalent Water Thickness" which represent the deviations of mass in terms of vertical extent of water in centimeters. See the provider's Monthly Mass Grids Overview for more details.

The GRACE Tellus (GRCTellus) Monthly Mass Grids Ocean dataset is produced by three centers: CSR (U. Texas / Center for Space Research), GFZ (GeoForschungsZentrum Potsdam), and JPL (NASA Jet Propulsion Laboratory). Each center is a part of the GRACE Ground System and generates Level-2 data (spherical harmonic fields) used in this dataset. The output includes spherical harmonic coefficients of the gravity field and of the dealiasing fields used to compute them. Since each center independently produces the coefficients, the results may be slightly different. It is recommended for most users to use the mean of all three datasets. See the provider's choosing a solution page for more details.

Note

  • Land leakage correction: Ocean signals are typically weaker than land signals, by factors of 2 and more, on seasonal and interannual time scales. To minimize leakage from high land signals onto ocean signals, a destriping filter has been applied which may cause cause correlations over much larger distances.

  • The GRCTellus Ocean datasets are optimized to examine regional ocean bottom pressure, but NOT intended to be spatially averaged to determine global mean ocean mass.

  • A filtered version of the GRCTellus Ocean dataset is also available which uses an alternative filtering method which may reduce leakage errors, and have results which agree better with altimetric sea surface height. NASA/GRACE/MASS_GRIDS/OCEAN_EOFR.

Bands

Resolution
1 arc degree

Bands

Name Units Min Max Description
lwe_thickness_csr cm -27* 36.81*

Equivalent liquid water thickness in centimeters calculated by CSR.

lwe_thickness_gfz cm -28.87* 33.02*

Equivalent liquid water thickness in centimeters calculated by GFZ.

lwe_thickness_jpl cm -26.03* 37.36*

Equivalent liquid water thickness in centimeters calculated by JPL.

* estimated min or max value

Image Properties

Image Properties

Name Type Description
CSR_END_TIME DOUBLE

End date in milliseconds of spherical harmonics solution from CSR.

CSR_START_TIME DOUBLE

Start date in milliseconds of spherical harmonics solution from CSR.

GFZ_END_TIME DOUBLE

End date in milliseconds of spherical harmonics solution from GFZ.

GFZ_START_TIME DOUBLE

Start date in milliseconds of spherical harmonics solution from GFZ.

JPL_END_TIME DOUBLE

End date in milliseconds of spherical harmonics solution from JPL.

JPL_START_TIME DOUBLE

Start date in milliseconds of spherical harmonics solution from JPL.

Terms of Use

Terms of Use

All NASA-produced data from the GRACE mission is made freely available for the public to use. When using any of the GRCTellus data, please add an acknowledgment: "GRACE land are available at http://grace.jpl.nasa.gov, supported by the NASA MEaSUREs Program." and cite with the citations provided.

Citations

Citations:
  • D.P. Chambers. 2012. GRACE MONTHLY OCEAN MASS GRIDS NETCDF RELEASE 5.0. Ver. 5.0. PO.DAAC, CA, USA. Dataset accessed [YYYY-MM-DD] at https://doi.org/10.5067/TEOCN-0N005.

  • Chambers, D.P. and J.A. Bonin: Evaluation of Release 05 time-variable gravity coefficients over the ocean. Ocean Science 8, 859-868, 2012. https://www.ocean-sci.net/8/859/2012.

  • Chambers D.P. and J. K. Willis: A Global Evaluation of Ocean Bottom Pressure from GRACE, OMCT, and Steric-Corrected Altimetry. J. of Oceanic and Atmosph. Technology, vol 27, pp 1395-1402. doi: 10.1175/2010JTECHO738.1, 2010.

Explore in Earth Engine

var dataset = ee.ImageCollection('NASA/GRACE/MASS_GRIDS/OCEAN')
                  .filter(ee.Filter.date('2016-08-01', '2016-08-30'));
var equivalentWaterThicknessCsr = dataset.select('lwe_thickness_csr');
var equivalentWaterThicknessCsrVis = {
  min: -10.0,
  max: 10.0,
};
Map.setCenter(6.746, 46.529, 1);
Map.addLayer(
    equivalentWaterThicknessCsr, equivalentWaterThicknessCsrVis,
    'Equivalent Water Thickness CSR');