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dc.contributor.authorCenedese, Claudia  Concept link
dc.contributor.authorAdduce, Claudia  Concept link
dc.contributor.authorFratantoni, David M.  Concept link
dc.date.accessioned2010-05-26T13:47:19Z
dc.date.available2010-05-26T13:47:19Z
dc.date.issued2005-09-30
dc.identifier.citationJournal of Geophysical Research 110 (2005): C09023en_US
dc.identifier.urihttps://hdl.handle.net/1912/3522
dc.descriptionAuthor Posting. © American Geophysical Union, 2005. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 110 (2005): C09023, doi:10.1029/2004JC002734.en_US
dc.description.abstractThe present study investigates the interaction between a self-propagating cyclonic vortex with two right vertical cylinders and determines the conditions for a vortex to bifurcate into two or more vortices. As in previous studies, after the cyclonic vortex came in contact with a cylinder, fluid peeled off the outer edge of the vortex and a so-called “streamer” went around the cylinder in a counterclockwise direction. Under the right conditions, this fluid formed a new cyclonic vortex in the wake of the cylinder, causing bifurcation of the original vortex into two vortices. In some cases, two streamers formed and went around the two cylinders, each forming a new cyclonic vortex. During the experiments, three parameters were varied: G, the separation between the cylinders; d, the diameter of the incident vortex; and y, the distance of the center of the vortex from an axis passing through the center of the gap between the cylinders. The number of vortices generated by the interaction depends on the ratio G/d and on the geometry of the encounter, which is given by the ratio y/g, where g = G/2. An unexpected and revealing result was the formation of a dipole vortex downstream of the two islands for values of −2 < y/g < 0, 0.25 ≤ G/d ≤ 0.4, and Re G > 200, where Re G = U G G/ν is the Reynolds number and U G is the maximum velocity of the vortex fluid in the gap. A possible mechanism is that the flow within the vortex was funneled between the two islands, and provided it had a sufficiently high velocity, a dipole formed, much like water ejected from a circular nozzle generates a dipole ring. The formation of a vortex of opposite sign to the incident vortex (i.e., anticyclonic) is in agreement with recent observations of North Brazil Current (NBC) rings interacting with the islands of Saint Vincent and Barbados in the eastern Caribbean. The passage between the islands of Saint Vincent and Barbados has values of G/d of approximately 0.5; hence the laboratory result suggests that both cyclonic and anticyclonic vortices could form downstream of them.en_US
dc.description.sponsorshipSupport was given by the National Science Foundation project OCE-0081756.en_US
dc.format.mimetypeapplication/pdf
dc.language.isoen_USen_US
dc.publisherAmerican Geophysical Unionen_US
dc.relation.urihttps://doi.org/10.1029/2004JC002734
dc.subjectMesoscale vorticesen_US
dc.subjectTopographyen_US
dc.subjectLaboratory experimentsen_US
dc.titleLaboratory experiments on mesoscale vortices interacting with two islandsen_US
dc.typeArticleen_US
dc.identifier.doi10.1029/2004JC002734


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