Measurements of a barotropic planetary vorticity mode in an eddy-resolving quasi-geostrophic model using acoustic tomography

A tomographic array is placed in a 2-layer, flat bottom, steady-wind driven quasi-geostrophic circulation model to investigate whether the analysis of acoustic travel time changes can detect large-scale barotropic oscillations. Time series of sea surface elevation and upper and lower layer meridional currents are generated for comparison against a series of acoustic travel times. The spectra of these time series exhibit a broad mesoscale peak near a period of 40 days. The spectrum of the acoustic travel time contains a significant peak due to a resonant barotropic oscillation with a period of 28.6 days which is not present in the spectra of the point measurements. In this numerical model, basin-scale tomographic measurements are a better method of sensing the large-scale resonant barotropic oscillations than are conventional point measurements because the tomographic system attenuates the "noise" from the mesoscale.

Grantor dc:publisher

Massachusetts Institute of Technology and Woods Hole Oceanographic Institution

Year dc:date.issued

1988

Author dc:creator

• Lawrence, Wendy B.

• Ocean circulation

Language dc:language.iso

en_US

DOI

10.1575/1912/4318

OAI identifier oai:identifier

oai:darchive.mblwhoilibrary.org:1912/4318