A NUMERICAL STUDY OF 3-DIMENSIONAL DENSE BOTTOM PLUMES ON A SOUTHERN-OCEAN CONTINENTAL-SLOPE

Citation
L. Jiang et Rw. Garwood, A NUMERICAL STUDY OF 3-DIMENSIONAL DENSE BOTTOM PLUMES ON A SOUTHERN-OCEAN CONTINENTAL-SLOPE, J GEO RES-O, 100(C9), 1995, pp. 18471-18488
Citations number
37
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Oceanografhy
Journal title
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
ISSN journal
2169-9275 → ACNP
Volume
100
Issue
C9
Year of publication
1995
Pages
18471 - 18488
Database
ISI
SICI code
2169-9275(1995)100:C9<18471:ANSO3D>2.0.ZU;2-F
Abstract
Three-dimensional features of dense bottom plumes flowing over contine ntal slopes, with or without along-slope topographic variations, are i nvestigated by simulating the evolution of a density front at a Southe rn Ocean continental shelf break, using a three-dimensional, primitive equation numerical model with a second-order turbulence closure schem e embedded. The focus of our investigation is the role of topography i n determining mixing and the offshore transport of dense shelf water d uring the transient adjustment process of a density front over a conti nental slope. We compare and discuss the numerical simulations for two cases: a uniform shelf and slope case and a case with a canyon that l eads from the coast to the deep ocean crossing the shelf and the slope . The numerical simulations indicate that baroclinic instability, plan etary rotation, bottom friction, and topography play major roles in de termining the surface and bottom plume formation, the growth and penet ration depth of the bottom plumes, and the characteristics of water ma ss on the slope. Mesoscale eddies play a fundamental role in transport ing mass, heat, and salt from shelf to deep ocean. The effects of the depth and width of the canyon are examined with two more experiments. The presence of a wide and deep canyon in the continental shelf and sl ope enhances considerably the drainage of coastal shelf water into the deep ocean.