Slope/shelf circulation and cross-slope/shelf transport out of a bay driven by eddies from the open ocean
Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution September 2009 Interaction between the Antarctic Circumpolar Current and the continental slope/shelf in the Marguerite...
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Massachusetts Institute of Technology and Woods Hole Oceanographic Institution
2009
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ftwhoas:oai:darchive.mblwhoilibrary.org:1912/3136 2023-05-15T13:53:14+02:00 Slope/shelf circulation and cross-slope/shelf transport out of a bay driven by eddies from the open ocean Zhang, Yu Marguerite Bay Western Antarctic Peninsula 2009-09 application/pdf https://hdl.handle.net/1912/3136 en_US eng Massachusetts Institute of Technology and Woods Hole Oceanographic Institution WHOI Theses https://hdl.handle.net/1912/3136 doi:10.1575/1912/3136 doi:10.1575/1912/3136 Ocean currents Ocean circulation Thesis 2009 ftwhoas https://doi.org/10.1575/1912/3136 2022-05-28T22:57:51Z Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution September 2009 Interaction between the Antarctic Circumpolar Current and the continental slope/shelf in the Marguerite Bay and west Antarctic Peninsula is examined as interaction between a wind-driven channel flow and a zonally uniform slope with a bay-shaped shelf to the south. Two control mechanisms, eddy advection and propagation of topographic waves, are identified in barotropic vortex-escarpment interactions. The two mechanisms advect the potential vorticity (PV) perturbations in opposite directions in anticyclone-induced interactions but in the same direction in cyclone-induced interactions, resulting in dramatic differences in the two kinds of interactions. The topographic waves become more nonlinear near the western(eastern if in the Northern Hemisphere) boundary of the bay, where strong cross-escarpment motion occurs. In the interaction between a surface anticyclone and a slope penetrating into the upper layer in a two-layer isopycnal model, the eddy advection decays on length scales on the order of the internal deformation radius, so shoreward over a slope that is wider than the deformation radius, the wave mechanism becomes noticeably significant. It acts to spread the cross-isobath transport in a much wider range while the transport directly driven by the anticyclone is concentrated in space. A two-layer wind-driven channel flow is constructed to the north of the slope in the Southern Hemisphere, spontaneously generating eddies through baroclinic instability. A PV front forms in the first layer shoreward of the base of the topography due to the lower-layer eddy-slope interactions. Perturbed by the jet in the center of the channel, the front interacts with the slope/shelf persistently yet episodically, driving a clockwise mean circulation within the bay as well as crossisobath transport. Both the transports across the ... Thesis Antarc* Antarctic Antarctic Peninsula Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server) Antarctic Antarctic Peninsula Marguerite ENVELOPE(141.378,141.378,-66.787,-66.787) Marguerite Bay ENVELOPE(-68.000,-68.000,-68.500,-68.500) The Antarctic Woods Hole, MA |
institution |
Open Polar |
collection |
Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server) |
op_collection_id |
ftwhoas |
language |
English |
topic |
Ocean currents Ocean circulation |
spellingShingle |
Ocean currents Ocean circulation Zhang, Yu Slope/shelf circulation and cross-slope/shelf transport out of a bay driven by eddies from the open ocean |
topic_facet |
Ocean currents Ocean circulation |
description |
Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution September 2009 Interaction between the Antarctic Circumpolar Current and the continental slope/shelf in the Marguerite Bay and west Antarctic Peninsula is examined as interaction between a wind-driven channel flow and a zonally uniform slope with a bay-shaped shelf to the south. Two control mechanisms, eddy advection and propagation of topographic waves, are identified in barotropic vortex-escarpment interactions. The two mechanisms advect the potential vorticity (PV) perturbations in opposite directions in anticyclone-induced interactions but in the same direction in cyclone-induced interactions, resulting in dramatic differences in the two kinds of interactions. The topographic waves become more nonlinear near the western(eastern if in the Northern Hemisphere) boundary of the bay, where strong cross-escarpment motion occurs. In the interaction between a surface anticyclone and a slope penetrating into the upper layer in a two-layer isopycnal model, the eddy advection decays on length scales on the order of the internal deformation radius, so shoreward over a slope that is wider than the deformation radius, the wave mechanism becomes noticeably significant. It acts to spread the cross-isobath transport in a much wider range while the transport directly driven by the anticyclone is concentrated in space. A two-layer wind-driven channel flow is constructed to the north of the slope in the Southern Hemisphere, spontaneously generating eddies through baroclinic instability. A PV front forms in the first layer shoreward of the base of the topography due to the lower-layer eddy-slope interactions. Perturbed by the jet in the center of the channel, the front interacts with the slope/shelf persistently yet episodically, driving a clockwise mean circulation within the bay as well as crossisobath transport. Both the transports across the ... |
format |
Thesis |
author |
Zhang, Yu |
author_facet |
Zhang, Yu |
author_sort |
Zhang, Yu |
title |
Slope/shelf circulation and cross-slope/shelf transport out of a bay driven by eddies from the open ocean |
title_short |
Slope/shelf circulation and cross-slope/shelf transport out of a bay driven by eddies from the open ocean |
title_full |
Slope/shelf circulation and cross-slope/shelf transport out of a bay driven by eddies from the open ocean |
title_fullStr |
Slope/shelf circulation and cross-slope/shelf transport out of a bay driven by eddies from the open ocean |
title_full_unstemmed |
Slope/shelf circulation and cross-slope/shelf transport out of a bay driven by eddies from the open ocean |
title_sort |
slope/shelf circulation and cross-slope/shelf transport out of a bay driven by eddies from the open ocean |
publisher |
Massachusetts Institute of Technology and Woods Hole Oceanographic Institution |
publishDate |
2009 |
url |
https://hdl.handle.net/1912/3136 |
op_coverage |
Marguerite Bay Western Antarctic Peninsula |
long_lat |
ENVELOPE(141.378,141.378,-66.787,-66.787) ENVELOPE(-68.000,-68.000,-68.500,-68.500) |
geographic |
Antarctic Antarctic Peninsula Marguerite Marguerite Bay The Antarctic |
geographic_facet |
Antarctic Antarctic Peninsula Marguerite Marguerite Bay The Antarctic |
genre |
Antarc* Antarctic Antarctic Peninsula |
genre_facet |
Antarc* Antarctic Antarctic Peninsula |
op_source |
doi:10.1575/1912/3136 |
op_relation |
WHOI Theses https://hdl.handle.net/1912/3136 doi:10.1575/1912/3136 |
op_doi |
https://doi.org/10.1575/1912/3136 |
op_publisher_place |
Woods Hole, MA |
_version_ |
1766258223174647808 |