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Description

This dataset contains monthly-averaged ocean velocity interpolated to a regular 0.5-degree grid from the ECCO Version 4 revision 4 (V4r4) ocean and sea-ice state estimate. Estimating the Circulation and Climate of the Ocean (ECCO) ocean and sea-ice state estimates are dynamically and kinematically-consistent reconstructions of the three-dimensional, time-evolving ocean, sea-ice, and surface atmospheric states. ECCO V4r4 is a free-running solution of the 1-degree global configuration of the MIT general circulation model (MITgcm) that has been fit to observations in a least-squares sense. Observational data constraints used in V4r4 include sea surface height (SSH) from satellite altimeters [ERS-1/2, TOPEX/Poseidon, GFO, ENVISAT, Jason-1,2,3, CryoSat-2, and SARAL/AltiKa]; sea surface temperature (SST) from satellite radiometers [AVHRR], sea surface salinity (SSS) from the Aquarius satellite radiometer/scatterometer, ocean bottom pressure (OBP) from the GRACE satellite gravimeter; sea ice concentration from satellite radiometers [SSM/I and SSMIS], and in-situ ocean temperature and salinity measured with conductivity-temperature-depth (CTD) sensors and expendable bathythermographs (XBTs) from several programs [e.g., WOCE, GO-SHIP, Argo, and others] and platforms [e.g.,research vessels, gliders, moorings, ice-tethered profilers, and instrumented pinnipeds]. V4r4 covers the period 1992-01-01T12:00:00 to 2018-01-01T00:00:00.

Product Summary

Platforms
MODELS ,
MITgcm
Spatial Extent

N: 90 S: -90 E: 180 W: -180

Spatial Resolution
0.5 Decimal Degrees x 0.5 Decimal Degrees
Location
GLOBAL OCEAN
Coordinate System
CARTESIAN
Granule Spatial Representation
CARTESIAN
Temporal Extent
1992-01-01 to 2018-01-01
Data Partner
Physical Oceanography Distributed Active Archive Center, Jet Propulsion Laboratory, NASA (NASA/JPL/PODAAC)
Concept ID
C1990404823-POCLOUD
Data State
COMPLETE
Number of Files/Granules
312
Processing Level
4
Published
Science Keywords
Ocean Circulation ,
Ocean Currents

Citation

Citation is critically important for dataset documentation and discovery. This dataset is openly shared, without restriction, in accordance with the EOSDIS Data Use and Citation Guidance.

Copy Citation

Fenty, I., & Wang, O. (2020). ECCO Ocean Velocity - Monthly Mean 0.5 Degree (Version 4 release 4) [Data set]. NASA Physical Oceanography Distributed Active Archive Center. https://doi.org/10.5067/ECG5M-OVE44 Date Accessed: 2026-03-15

Documents

Variables

The table below lists the variables contained within a single granule for this dataset. Variables often contain observed or derived geophysical measurements collected from a variety of sources, including remote sensing instruments on satellite and airborne platforms, field campaigns, in situ measurements, and model outputs. The terms variable, parameter, scientific data set, layer, and band have been used across NASA’s Earth science disciplines; however, variable is the designated nomenclature in NASA’s Common Metadata Repository (CMR). Variable metadata attributes such as Name, Description, Units, Data Type, Fill Value, Valid Range, and Scale Factor allow users to efficiently process and analyze the data. The full range of attributes may not be applicable to all variables. Additional information on variable attributes is typically available in the data, user guide, and/or other product documentation.

For questions on a specific variable, please use the Earthdata Forum.

Name Description Units Data Type Fill Value Valid Range Scale Factor Offset
EVEL Zonal (east-west) component of ocean velocity. Note: EVEL is calculated by interpolating the model's x and y components of ocean velocity (UVEL and VVEL)to tracer cell centers and then finding the zonal component of the interpolated vectors. It is not recommended to use EVEL and NVEL for volume budget calculations because interpolating UVEL and VVEL from the model grid to the lat-lon grid introduces errors. Perform volume budget calculations with UVELMASS and VVELMASS on the native model grid. m s-1 float 9.96921E+36 -129.3382 to 167.34177 1 N/A
latitude uniform grid spacing from -89.75 to 89.75 by 0.5 degrees_north float N/A N/A 1 N/A
latitude_bnds latitude bounds grid cells N/A float N/A N/A 1 N/A
longitude uniform grid spacing from -179.75 to 179.75 by 0.5 degrees_east float N/A N/A 1 N/A
longitude_bnds longitude bounds grid cells N/A float N/A N/A 1 N/A
NVEL Meridional (north-south) component of ocean velocity. Note: NVEL is calculated by interpolating the model's x and y components of ocean velocity (UVEL and VVEL) to tracer cell centers and then finding the meridional component of the interpolated vectors. It is not recommended to use EVEL and NVEL for volume budget calculations because interpolating UVEL and VVEL from the model grid to the lat-lon grid introduces errors. Perform volume budget calculations with UVELMASS and VVELMASS on the native model grid. m s-1 float 9.96921E+36 -92.33054 to 133.24715 1 N/A
time center time of averaging period hours since 1992-01-01T12:00:00 int N/A N/A 1 N/A
time_bnds Start and end times of averaging period. N/A int N/A N/A 1 N/A
WVEL Vertical velocity in the +z direction at the top face of the grid cell. Note: in the Arakawa-C grid used in ECCO V4r4, vertical velocities are staggered relative to the tracer cell centers with values at the TOP and BOTTOM faces of each grid cell. m s-1 float 9.96921E+36 -0.10404494 to 0.057065234 1 N/A
Z Non-uniform vertical spacing. m float N/A N/A 1 N/A
Z_bnds One pair of bounds for each vertical level. N/A float N/A N/A 1 N/A
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