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Variability of Cross-Slope Flow in the Desoto Canyon Region

Title: Variability of Cross-Slope Flow in the Desoto Canyon Region.
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Name(s): Nguyen, Thanh Tam, author
Chassignet, Eric P., professor directing thesis
Dukhovskoy, Dmitry, committee member
Huettel, Markus, committee member
Morey, Steven L., committee member
Dewar, William, committee member
Florida State University, degree granting institution
College of Arts and Sciences, degree granting college
Department of Earth, Ocean, and Atmospheric Science, degree granting department
Type of Resource: text
Genre: text
Issuance: monographic
Date Issued: 2014
Publisher: Florida State University
Place of Publication: Tallahassee, Florida
Physical Form: computer
Physical Form: online resource
Extent: 1 online resource (79 pages)
Language(s): English
Abstract/Description: Cross-slope flow is critical for governing heat and material exchange, including pollutants and biota, between the coastal and deep ocean. This study focuses on characterizing the variability of cross-slope near-bottom flow in the DeSoto Canyon region, where the BP's Macondo well exploded in April 2010, using a multi-decadal HYbrid Coordinate Ocean Model (HYCOM) simulation of Gulf of Mexico circulation. Due to change in shelf orientation east and west of the canyon, wind-driven vertical motions are mostly related to a component of the local wind vector along an angle that may deviate from the local isobaths, with smaller deviations from the along-isobath direction to the east of the canyon and bigger departures to the west. This implies that upwelling is associated with along-isobath winds east of the canyon but shelf waves propagating from the eastern shelf, where northwesterly winds are upwelling favorable, influence cross-slope flow to the west of the canyon. Beyond the shelf break, where the Loop Current and its eddies can directly impact the depth of isotherms, the isotherms are deepened underneath the Loop Current and anticyclones but uplifted on their inshore periphery. The Loop Current also interacts with the west Florida shelf and generates a high pressure gradient that extends northward along the continental slope into the study domain. Consequently, large-scale and persistent upwelling and downwelling events take place over the continental slope of the domain. The vertical excursions mostly range from ±35 to ± 50 m for the shallow isopycnals but can reach to over ± 100 m. Most distinct upwelling and downwelling events are short duration on the order of days, however there is a significant chance for persistent events, which can be induced by either remote or direct interaction of the Loop Current and/or eddies with the slope.
Identifier: FSU_migr_etd-9222 (IID)
Submitted Note: A Thesis submitted to the Department of Earth, Ocean, and Atmospheric Science in partial fulfillment of the requirements for the degree of Master of Science.
Degree Awarded: Fall Semester, 2014.
Date of Defense: September 24, 2014.
Keywords: cross-slope flow, DeSoto Canyon region, Loop Current's impact, mesoscale circulation, upwelling and downwelling, wind-driven upwelling
Bibliography Note: Includes bibliographical references.
Advisory Committee: Eric Chassignet, Professor Directing Thesis; Dmitry Dukhovskoy, Committee Member; Markus Huettel, Committee Member; Steven Morey, Committee Member; William Dewar, Committee Member.
Subject(s): Oceanography
Persistent Link to This Record: http://purl.flvc.org/fsu/fd/FSU_migr_etd-9222
Owner Institution: FSU