Seasonal variation of ocean bottom pressure derived from Gravity Recovery and Climate Experiment (GRACE) : local validation and global patterns
Chave, Alan D.
MetadataShow full item record
KeywordGravity; Geoid; Ocean bottom pressure; Deep ocean currents; Ocean tides; In situ measurements
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.
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.
Showing items related by title, author, creator and subject.
A comparison of in situ bottom pressure array measurements with GRACE estimates in the Kuroshio Extension Park, Jae-Hun; Watts, D. Randolph; Donohue, Kathleen A.; Jayne, Steven R. (American Geophysical Union, 2008-09-10)Ocean bottom pressure estimates from Gravity Recovery and Climate Experiment (GRACE) have been validated by comparisons with an array of in situ bottom pressure measurements. The 600 km by 600 km array comprised 46 bottom ...
An experimental study on mixing induced by gravity currents on a sloping bottom in a rotating fluid Ohiwa, Mitchihiro (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2002-09)Mixing induced by gravity currents on a sloping bottom was studied through laboratory experiments in a rotating fluid. The dense fluid on the sloping bottom formed a gravity current that could be in regimes where the ...
Three-dimensional acoustic propagation through shallow water internal, surface gravity and bottom sediment waves Shmelev, Alexey A. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2011-09)This thesis describes the physics of fully three-dimensional low frequency acoustic interaction with internal waves, bottom sediment waves and surface swell waves that are often observed in shallow waters and on continental ...