A Simple Model for Deep Equatorial Zonal Currents Forced at Lateral BoundariesSource: Journal of Physical Oceanography:;1989:;Volume( 019 ):;issue: 012::page 1881Author:Ponte, Rui M.
DOI: 10.1175/1520-0485(1989)019<1881:ASMFDE>2.0.CO;2Publisher: American Meteorological Society
Abstract: Deep lateral boundary processes (e.g., western boundary currents) are hypothesized as an alternative energy source exciting the equatorial wave guide at long time scales. A linear, continuously stratified model is used to study the equatorial zonal currents generated by a time dependent, short vertical scale deep zonal jet located at the meridional walls and centered at the equator. Examples of solutions with periodic, transient and spectral forcing are presented. For low frequency forcing at the western or eastern boundaries, energy travels from the source along ray paths associated with Kelvin and long Rossby waves, respectively. Linearly damped solutions look similar in both cases. Solutions show in general a rich baroclinic structure and a complex time dependence (e.g., periodic solutions can exhibit both upward and downward phase propagation and standing mode oscillations at different depths in the water column), with the vertical structure depending, among other factors, on the vertical scale and frequency composition assumed for the boundary jet. Results suggest the potential importance of deep forcing mechanisms to the existence of long time scale, deep baroclinic currents in the equatorial ocean. Solutions are qualitatively similar to observations of the equatorial deep jets, but any detailed comparison between model results and data is premature, given the lack of observational knowledge about the time scales, strength and spatial distribution of deep energy sources.
|
Collections
Show full item record
contributor author | Ponte, Rui M. | |
date accessioned | 2017-06-09T14:49:27Z | |
date available | 2017-06-09T14:49:27Z | |
date copyright | 1989/12/01 | |
date issued | 1989 | |
identifier issn | 0022-3670 | |
identifier other | ams-27586.pdf | |
identifier uri | http://onlinelibrary.yabesh.ir/handle/yetl/4164607 | |
description abstract | Deep lateral boundary processes (e.g., western boundary currents) are hypothesized as an alternative energy source exciting the equatorial wave guide at long time scales. A linear, continuously stratified model is used to study the equatorial zonal currents generated by a time dependent, short vertical scale deep zonal jet located at the meridional walls and centered at the equator. Examples of solutions with periodic, transient and spectral forcing are presented. For low frequency forcing at the western or eastern boundaries, energy travels from the source along ray paths associated with Kelvin and long Rossby waves, respectively. Linearly damped solutions look similar in both cases. Solutions show in general a rich baroclinic structure and a complex time dependence (e.g., periodic solutions can exhibit both upward and downward phase propagation and standing mode oscillations at different depths in the water column), with the vertical structure depending, among other factors, on the vertical scale and frequency composition assumed for the boundary jet. Results suggest the potential importance of deep forcing mechanisms to the existence of long time scale, deep baroclinic currents in the equatorial ocean. Solutions are qualitatively similar to observations of the equatorial deep jets, but any detailed comparison between model results and data is premature, given the lack of observational knowledge about the time scales, strength and spatial distribution of deep energy sources. | |
publisher | American Meteorological Society | |
title | A Simple Model for Deep Equatorial Zonal Currents Forced at Lateral Boundaries | |
type | Journal Paper | |
journal volume | 19 | |
journal issue | 12 | |
journal title | Journal of Physical Oceanography | |
identifier doi | 10.1175/1520-0485(1989)019<1881:ASMFDE>2.0.CO;2 | |
journal fristpage | 1881 | |
journal lastpage | 1891 | |
tree | Journal of Physical Oceanography:;1989:;Volume( 019 ):;issue: 012 | |
contenttype | Fulltext |