Effects of shoaling bottom topography on the dynamics of Gulf Stream cyclonic rings.
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| Format: | Thesis Book |
| Language: | English |
| Published: |
1981.
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| Online Access: | Link to ProQuest Copy Link to OAKTrust copy |
| Abstract: | A two-layer, rigid-lid model of a Boussinesq, quasi-geostrophic ocean, based on the vertically-integrated equations of motion, is used on a (beta)-plane to study the processes involved as an initially-Gaussian cyclonic ring translates into a continental shelf. Initial tests of geostrophy, rotation, nonlinearity, lateral frictional effects and topography yield values of energy decay and partitioning and centroid propagation speeds in close proximity to those predicted by and extrapolated from linear theory. A series of six 60-day simulations, based on the parameterization of an actual Gulf Stream-derived ring, are used to study the combined effects of baroclinicity (defined as the ratio of maximum lower layer velocity to maximum upper layer velocity) and topography as a ring propagates up a numerical parameterization of the Blake Plateau. Model results are compared to actual ring measurements and subsequent data analyses. Nonlinear terms in the equations of motion are found to have a stabilizing effect on ring decay. A greater slope results in an increased westerly and decreased northerly component of motion. Baroclinicity yields an increase in both northerly and westerly translation. Slope inhibits the propagation of the barotropic mode and appears to stabilize ring spin-down. Velocities tend to converge to a common value with initially-different values of baroclinicity. Increased baroclinicity decreases ring lifetime. An anomalous behavior results in the case where velocities in the upper and lower layers are initially opposite in direction. |
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| Item Description: | "Major subject: Oceanography." Typescript (photocopy). Vita. |
| Physical Description: | xix, 254 leaves : illustrations ; 29 cm |
| Bibliography: | Includes bibliographical references (leaves 191-200). |