Ocean angular momentum and the Earth's variable rotation and gravity field

Author: Rui M. Ponte
Date: 
October 16, 2001
Type: 
Presentation
Venue: 
IAPSO/IABO Joint Assemblies, Mar del Plata
Citation: 

Ponte, R.M., 2001. Ocean angular momentum and the Earth's variable rotation and gravity field, IAPSO/IABO Joint Assemblies, Mar del Plata, October 2001.

Variability in ocean currents and bottom pressure can lead to changes in global ocean angular momentum (OAM) and affect the gravitational field and rotation of the Earth. Studies of OAM can thus provide an integrated measure of the variability in ocean circulation and mass fields, shed light on the momentum flux mechanisms responsible for OAM transfers to the atmosphere and solid Earth, and contribute to the understanding of the Earth's variable rotation and gravity field. We will review what has been learned recently about OAM from analysis of a number of different ocean general circulation models. Topics to be discussed include the relative importance of circulation and bottom pressure effects to variability in OAM, the relation of OAM to gravity field changes, and the impact of data assimilation on the estimation of OAM and related quantities, on timescales from days to years. We will discuss the potential impact of satellite gravity data on OAM studies and explore useful means of combining altimeter and gravity data, Earth rotation data, and ocean models to address various oceanographic and geodetic research questions.