Geodetic Variables

The ocean is a key factor in determining and understanding the geodetic properties (geometric shape, orientation in space, and gravity field) of the Earth. For example, changes in the oceanic mass field can have important effects on crustal loading. Knowledge of the mean ocean surface circulation and dynamic topography can help determine the marine geoid and the gravity field. And variability in both ocean currents and bottom pressure can affect the Earth's orientation in space. ECCO products make it possible to calculate geodetically relevant quantities such as the ocean angular momentum and center of mass.

Effects of ocean tides are not included in any of these geodetic variables. In addition, all quantities except those based on V4r4 do not consider surface atmospheric pressure effects. For V4r4, two sets are provided based on sea level with and without the inverted barometer signal removed. Similarly, effects of net freshwater flux into the ocean, related to barystatic sea level, are only considered in the latest releases (V4r3, V4r4), for which two sets are provided based on values with and without those effects included. Some variables are provided hourly but variability at periods shorter than 12 hours are not expected to be realistic.

Download the data using the button. Clicking on the icon will take you to Google Drive* instead. A description of each dataset is included in each data file, and as a preview using the "view metadata" button. Variables here are derived from a subset of ECCO products to facilitate geodetic studies.

Data: International Earth Rotation & Reference Systems Service
Acronyms: CoM: Center-of-Mass; FWF: Freshwater Flux; IB: Inverted Barometer; OAM: Oceanic Angular Momentum; OBP: Ocean Bottom Pressure

Global Oceanic Angular Momentum (OAM) & Excitation Functions

FileStatusOcean ModelDate SpanResolutionContents
ECCO_v4r4_noIBremoved_yesFWF.oam
 
MITgcmJan 1992 – Dec 20171 hourOAM (with FWF; no IB signal removed)
ECCO_v4r4_noIBremoved_noFWF.oam
 
MITgcmJan 1992 – Dec 20171 hourOAM (w/o FWF; no IB signal removed)
ECCO_v4r4_IBremoved_yesFWF.oam
 
MITgcmJan 1992 – Dec 20171 hourOAM (with FWF; IB signal removed)
ECCO_v4r4_IBremoved_noFWF.oam
 
MITgcmJan 1992 – Dec 20171 hourOAM (w/o FWF; IB signal removed)
ECCO_v4r3_yesFWF.oam
 
deprecated (see ECCO_v4r4_yesFWF.oam)MITgcmJan 1992 – Dec 20151 hourOAM (with FWF)
ECCO_v4r3_noFWF.oam
 
deprecated (see ECCO_v4r4_noFWF.oam)MITgcmJan 1992 – Dec 20151 hourOAM (w/o FWF)
ECCO_kf080i.chi
 
MITgcmJan 1993 – Mar 20201 dayexcitation
ECCO_kf080i.oam
 
MITgcmJan 1993 – Mar 20201 dayOAM
ECCO_kf079.chi
 
MITgcmJan 1993 – Mar 20201 dayexcitation
ECCO_kf079.oam
 
MITgcmJan 1993 – Mar 20201 dayOAM
ECCO_kf066b.chi
 
deprecated (see kf080i.chi)MITgcmJan 1993 – Dec 20081 dayexcitation
ECCO_kf066b.oam
 
deprecated (see kf080i.oam)MITgcmJan 1993 – Dec 20081 dayOAM
ECCO_kf066a2.chi
 
deprecated (see kf079.chi)MITgcmJan 1993 – Dec 20081 dayexcitation
ECCO_kf066a2.oam
 
deprecated (see kf079.oam)MITgcmJan 1993 – Dec 20081 dayOAM
ECCO_kf049f.oam
 
deprecated (see kf080i.oam)MITgcmJan 1993 – Mar 20061 dayOAM

Oceanic Center-of-Mass

FileStatusOcean ModelDate SpanResolutionContents
ECCO_v4r4_yesFWF.cm
 
MITgcmJan 1992 – Dec 20171 hourCoM (with FWF)
ECCO_v4r4_noFWF.cm
 
MITgcmJan 1992 – Dec 20171 hourCoM (w/o FWF)
ECCO_v4r3_yesFWF.cm
 
deprecated (see ECCO_v4r4_yesFWF.cm)MITgcmJan 1992 – Dec 20151 hourCoM (with FWF)
ECCO_v4r3_noFWF.cm
 
deprecated (see ECCO_v4r4_noFWF.cm)MITgcmJan 1992 – Dec 20151 hourCoM (w/o FWF)
ECCO_kf080i.cm
 
MITgcmJan 1993 – Mar 20201 dayCoM
ECCO_kf079.cm
 
MITgcmJan 1993 – Mar 20201 dayCoM
ECCO_kf066b.cm
 
deprecated (see kf080i.cm)MITgcmJan 1993 – Dec 20081 dayCoM
ECCO_kf066a2.cm
 
deprecated (see kf079.cm)MITgcmJan 1993 – Dec 20081 dayCoM
ECCO_kf049f.cm
 
deprecated (see kf080i.cm)MITgcmJan 1993 – Mar 20061 dayCoM

Ocean-Bottom Pressure

FileStatusOcean ModelDate SpanResolutionContents
ECCO v4-r4 OBPNOPAB
 
MITgcmJan 1992 – Dec 20171 dayOBP
ECCO v4-r4 OBP
 
MITgcmJan 1992 – Dec 20171 dayOBP
ECCO_kf080i.obp
 
MITgcmJan 1993 – present1 dayOBP
*ECCO Drive requires a NASA Earthdata Account for access.