N: 90 S: -90 E: 180 W: -180
Description
This dataset provides monthly-averaged global mean sea level from the ECCO Version 4 Release 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 and model sea level anomaly (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
Citation
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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 Sort descending | Description | Units | Data Type | Fill Value | Valid Range | Scale Factor | Offset |
|---|---|---|---|---|---|---|---|
| global_mean_barystatic_sea_level_anomaly | Global mean barystatic sea level anomaly due to changes in total ocean mass. Note: ECCOv4 uses a volume-conserving Boussinesq formulation of the MITgcm with a free-surface boundary condition with real freshwater flux forcing. Changes in ocean mass due to evaporation, precipitation, runoff, and sea-ice growth/melt are reflected in model sea level. However, as a consequence of the Boussinsq formulation, changes to seawater density due to net buoyancy fluxes (e.g., global mean surface heating/cooling) do not change model sea level anomaly (ETAN) via seawater expansion/contraction. Changes in global ocean density therefore induce a spurious change in model ocean bottom pressure (PHIBOT) via 'virtual mass fluxes'. The 'Greatbatch correction' is a time varying, globally-uniform correction to account for changes in global mean density in Boussinesq models. This correction is used to calculate dynamic sea surface height (SSH) and ocean bottom pressure (OBP). Importantly, there is no dynamical significance to the Greatbatch correction but it is required to account for steric changes in global sea level. See Greatbatch, 1994. J. of Geophys. Res. Oceans, doi.org/10.1029/94JC00847 | m | float | 9.96921E+36 | -0.044738118 to 0.043026384 | 1 | N/A |
| global_mean_sea_level_anomaly | Global mean of dynamic sea level anomaly, equivalent to global mean sea level change. Note: ECCOv4 uses a volume-conserving Boussinesq formulation of the MITgcm with a free-surface boundary condition with real freshwater flux forcing. Changes in ocean mass due to evaporation, precipitation, runoff, and sea-ice growth/melt are reflected in model sea level. However, as a consequence of the Boussinsq formulation, changes to seawater density due to net buoyancy fluxes (e.g., global mean surface heating/cooling) do not change model sea level anomaly (ETAN) via seawater expansion/contraction. Changes in global ocean density therefore induce a spurious change in model ocean bottom pressure (PHIBOT) via 'virtual mass fluxes'. The 'Greatbatch correction' is a time varying, globally-uniform correction to account for changes in global mean density in Boussinesq models. This correction is used to calculate dynamic sea surface height (SSH) and ocean bottom pressure (OBP). Importantly, there is no dynamical significance to the Greatbatch correction but it is required to account for steric changes in global sea level. See Greatbatch, 1994. J. of Geophys. Res. Oceans, doi.org/10.1029/94JC00847 | m | float | 9.96921E+36 | -0.055373594 to 0.054730136 | 1 | N/A |
| global_mean_sterodynamic_sea_level_anomaly | Steric sea level anomaly associated with seawater expansion/contraction due to density changes. Note: ECCOv4 uses a volume-conserving Boussinesq formulation of the MITgcm with a free-surface boundary condition with real freshwater flux forcing. Changes in ocean mass due to evaporation, precipitation, runoff, and sea-ice growth/melt are reflected in model sea level. However, as a consequence of the Boussinsq formulation, changes to seawater density due to net buoyancy fluxes (e.g., global mean surface heating/cooling) do not change model sea level anomaly (ETAN) via seawater expansion/contraction. Changes in global ocean density therefore induce a spurious change in model ocean bottom pressure (PHIBOT) via 'virtual mass fluxes'. The 'Greatbatch correction' is a time varying, globally-uniform correction to account for changes in global mean density in Boussinesq models. This correction is used to calculate dynamic sea surface height (SSH) and ocean bottom pressure (OBP). Importantly, there is no dynamical significance to the Greatbatch correction but it is required to account for steric changes in global sea level. See Greatbatch, 1994. J. of Geophys. Res. Oceans, doi.org/10.1029/94JC00847 | m | double | 9.9692099683869E+36 | -0.017452795300931 to 0.017312100615511 | 1 | N/A |