Ocean Bottom Pressure Variability

Ocean Bottom Pressure (OBP) variability as observed by GRACE/GRACE-FO is an integrated signal from a number of different processes. The GravIS OBP Level-3 products represent anomalies relative to the long-term mean over the period 2002/04 through 2020/03, provided in terms of cm of equivalent water height.

Gridded OBP Level-3 products are displayed in the spatial plot. These products contain several individual variables which can be selected by clicking on the respective name of a particular variable next to the spatial plot, or by using the corresponding pulldown menu in the spatial plot. The gridded products, provided in NetCDF format, can be downloaded from the ISDC archive, either based on gravity field time series from GFZ or COST-G .

For each selected variable, globally averaged anomalies as well as averaged anomalies for predefined regions (representing areas with similar characteristics based on an ocean model) are displayed in the time series plot. Click on the spatial plot to select a particular region. All available regional averaged OBP time series, provided as CSV files, can be directly downloaded from this site by clicking on the download button above the time series plot. The geometries of the predefined regions are available here .

Further information on the OBP data products and the applied processing scheme is available here as technical note.

GRACE: Barystatic sea-level

Pressure variations due to mass inflow from the continents and deformations of the equipotential surface coincident with mean sea-level due to gravitational attraction of masses at the continents.

GRACE: Residual circulation

Pressure variations due to the general ocean circulation not represented by the non-tidal de-aliasing model AOD1B; not corrected for spatial leakage.

GRACE: Spatial leakage

Bottom pressure variations likely caused by spatial leakage; intended as optional correction for the residual circulation component.

GRACE: Barystatic sea-level uncertainty

Spatially variable, temporally constant component of the uncertainty estimate for the GRACE-based barystatic sea-level variability, given as standard deviation.

GRACE: Residual circulation uncertainty

Time-variable component of the uncertainty estimate for the GRACE-based residual circulation variability, given as standard deviation.

Model: Atmospheric mass

Static contribution of atmospheric mass to ocean bottom pressure as represented in the non-tidal de-aliasing model AOD1B.

Model: Ocean circulation

Dynamic ocean component of ocean bottom pressure as represented in the non-tidal de-aliasing model AOD1B.

Contact:

Henryk Dobslaw (dobslaw (at) gfz-potsdam.de)

Citation of Data:

Level-3 products based on GFZ RL06:

Dobslaw, Henryk; Boergens, Eva; Dill, Robert, 2019:
GFZ GravIS RL06 Ocean Bottom Pressure Anomalies. V. 0005
GFZ Data Services, https://doi.org/10.5880/GFZ.GRAVIS_06_L3_OBP

Level-3 products based on COST-G RL01:

Dobslaw, Henryk; Boergens, Eva; Dill, Robert, 2020:
COST-G GravIS RL01 Ocean Bottom Pressure Anomalies. V. 0005
GFZ Data Services, https://doi.org/10.5880/COST-G.GRAVIS_01_L3_OBP