Publication Date:
2022-05-25
Description:
Author Posting. © American Geophysical Union, 2005. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 110 (2005): C09001, doi:10.1029/2004JC002772.
Description:
The Gravity Recovery and Climate Experiment (GRACE) processing centers at the GeoForschungsZentrum Potsdam (GFZ) and the University of Texas Center for Space Research (UTCSR) provide time series of monthly gravity field solutions covering the period since mission launch in March 2002. Although the achieved accuracy still remains an order of magnitude below the mission's baseline goal, these time series have successfully been used to study terrestrial phenomena such as water storage variations. Over the oceans, the monthly gravity field solutions can be converted into estimates of the fluctuating ocean bottom pressure (OBP), which is the sum of atmospheric and oceanic mass variations. The GRACE products may be validated against in situ OBP observations which are available from a ground truth site in the tropical northwest Atlantic Ocean. Large differences are observed between the in situ and GRACE-derived OBP which are investigated by comparing the tidal and nontidal ocean models used at GFZ and UTCSR for dealiasing short-term (〈2 months) mass variations from satellite measurements. Results show that the barotropic nontidal and tide models need improvement at periods shorter than 1 day and longer than 2 weeks. On a global scale the monthly OBP fields from GRACE generally overestimate the variability compared to ocean general circulation models, especially in tropical regions. This may be attributed to continuing deficiencies in GRACE data processing. Nevertheless, there is some initial evidence that GRACE possesses the potential to observe large-scale averages of bottom pressure fluctuations.
Description:
The German Ministry of Education and
Research (BMBF) supports the GRACE Science Data System at GFZ
within the Geotechnologien geoscientific R + D programme under grant
03F0326A. Support
for the MOVE experiment and analysis was provided by the Bundesministerium
für Bildung und Forschung within the German CLIVAR
programme (grants 03F0246A and 03F0377B) as well as by the Deutsche
Forschungsgemeinschaft (grant SE815/21). This work was supported at
WHOI by subcontract 1256603 from the Jet Propulsion Laboratory.
Keywords:
Gravity
;
Geoid
;
Ocean bottom pressure
;
Deep ocean currents
;
Ocean tides
;
In situ measurements
Repository Name:
Woods Hole Open Access Server
Type:
Article
Format:
application/pdf
Permalink
