A diagnostic study of the velocity structure of a meandering jet in the California current system using a primitive equation model
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Authors
Mallette, James R.
Subjects
Advisors
Haney, Robert L.
Date of Issue
1991-06
Date
1991 Jun
Publisher
Monterey, California. Naval Postgraduate School
Language
en_US
Abstract
A high resolution 20-level, primitive equation model is initialized using sigma-theta data acquired during a coastal Transition Zone (CTZ) cruise from 6 to 12 July 1988 near Point Arena, California for the purpose of diagnosing the three-dimensional dynamically balanced flow field for the region. The major feature in the region during the cruise period was a strong meandering jet which flowed equatorward and offshore, oriented in a northeast to southwest direction. A density diagnostic version of the model, in which the sigma-theta is held constant during the 72 hour integration time, is compared with a robust diagnostic version of the model, in which the sigma-theta field is allowed to adjust dynamically within the constraints of a damping time scale. The density diagnostic version of the model produces vertical velociteis which are an order of magnitude larger than vertical calculated from bio-optical data collected in the same location and at the same time as the CTZ cruise. The robust diagnostic version produced vertical velocities within the range of vertical velocities calculated from the bio-optical data. The horizontal pattern of vertical velocity from the robust diagnostic version also compared well with patterns seen in trough/ridge systems in the Gulf Stream. In particular, there is horizontal convergence and downwelling all along the offshore directed part of the meandering jet. Vertical cross-section comparisons between model velocity data and ADCP velocity data collected during the cruise revealed differences which may be caused by factors neglected by the model (e.g. bottom topography, wind forcing, and heat fluxes).
Type
Thesis
Description
Series/Report No
Department
Meteorology;Physical Oceanography
Organization
Naval Postgraduate School (U.S.)
Identifiers
NPS Report Number
Sponsors
Funder
Format
86 p.;28 cm.
Citation
Distribution Statement
Rights
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.