scholarly journals Stability of meridionally-flowing grounded abyssal currents in the ocean

2008 ◽  
Author(s):  
G. E. Swaters
Keyword(s):  
Abyssal Currents

Exploratory observations of abyssal currents in the South Atlantic near Vema Channel

1983 ◽  
Vol 41 (3) ◽  
pp. 487-510 ◽  
Author(s):  
William J. Schmitz ◽  
Nelson G. Hogg
Keyword(s):  
South Atlantic ◽  
The South ◽  
Abyssal Currents

How do western abyssal currents cross the equator?

1993 ◽  
Vol 40 (2) ◽  
pp. 235-255 ◽  
Author(s):  
Doron Nof ◽  
Donald B. Olson
Keyword(s):  
Abyssal Currents

The Meridional Flow of Source-Driven Abyssal Currents in a Stratified Basin with Topography. Part I: Model Development and Dynamical Properties

2006 ◽  
Vol 36 (3) ◽  
pp. 335-355 ◽  
Author(s):  
Gordon E. Swaters
Keyword(s):  
Baroclinic Instability ◽  
Model Development ◽  
Finite Amplitude ◽  
Meridional Flow ◽  
Gravity Models ◽  
Western Boundary ◽  
Reduced Gravity ◽  
The Stability ◽  
Abyssal Currents ◽  
Variable Topography

Abstract The equatorward flow of source-driven grounded deep western boundary currents within a stratified basin with variable topography is examined. The model is the two-layer quasigeostrophic (QG) equations, describing the overlying ocean, coupled to the finite-amplitude planetary geostrophic (PG) equations, describing the abyssal layer, on a midlatitude β plane. The model retains subapproximations such as classical Stommel–Arons theory, the Nof abyssal dynamical balance, the so-called planetary shock wave balance (describing the finite-amplitude β-induced westward propagation of abyssal anomalies), and baroclinic instability. The abyssal height field can possess groundings. In the reduced gravity limit, a new nonlinear steady-state balance is identified that connects source-driven equatorward abyssal flow (as predicted by Stommel–Arons theory) and the inertial topographically steered deep flow described by Nof dynamics. This model is solved explicitly, and the meridional structure of the predicted grounded abyssal flow is described. In the fully baroclinic limit, a variational principle is established and is exploited to obtain general stability conditions for meridional abyssal flow over variable topography on a β plane. The baroclinic coupling of the PG abyssal layer with the QG overlying ocean eliminates the ultraviolet catastrophe known to occur in inviscid PG reduced gravity models. The baroclinic instability problem for a constant-velocity meridional abyssal current flowing over sloping topography with β present is solved and the stability characteristics are described.

Intra-seasonal Oscillation of Abyssal Currents in the Middle East Pacific Ocean

2020 ◽  
Author(s):  
Fangfang Kuang ◽  
Junpeng Zhang ◽  
Aijun Pan ◽  
Dayong Zhu
Keyword(s):  
Pacific Ocean ◽  
Middle East ◽  
Kinetic Energy ◽  
Low Frequency ◽  
Zonal Flow ◽  
Bottom Layer ◽  
East Pacific ◽  
Seasonal Oscillation ◽  
East Pacific Ocean ◽  
Abyssal Currents

<p>In this work, the intra-seasonal oscillation of the abyssal currents in the Middle East Pacific Ocean is investigated using direct observations from ADCP instruments, which are mounted on a subsurface mooring deployed at 154oW，10oN. The observation shows that the intra-seasonal (20-100 days) oscillation part of the kinetic energy accounts for more than 40% of the low-frequency flow kinetic energy between 200~2000m, while accounts for more than 50% under 2000m; the intra-seasonal oscillation of meridional flow is more obvious than that of zonal flow. The meridional velocity in the upper layer (100-1000m) shows an oscillation at periods of 50~90 days, which is most obvious at the depth of 500m; from 200m to the bottom layer currents shows an synchronous oscillation at a period of 30 days lasting for several months, and the oscillation signal is the strongest in the deep layer (4600m); The correlation is good between the 20~40 day band passed meridional current at the bottom layer and that of the geostrophic current. The observed temperature of 4000m and 5000m also shows similar characteristics of 30 days period oscillation, which has good correlation to the sea level height. The reanalysis data shows the 30 days oscillation of the abyssal currents is propagated from west to east at a speed of about 0.29m/s while the 40~100 day oscillation is propagated at a speed of about 0.1m/s; the intensity of the intra-seasonal oscillation has obvious interannual variations, which may be related to the change of the eddy energy of the sea surface.</p>

Abyssal currents and advection of resuspended sediment along the northeastern Bermuda Rise

1994 ◽  
Vol 119 (1-2) ◽  
pp. 159-171 ◽  
Author(s):  
Edward P Laine ◽  
Wilford D Gardner ◽  
Mary Jo Richardson ◽  
Michelle Kominz
Keyword(s):  
Bermuda Rise ◽  
Abyssal Currents

Abyssal Currents

2019 ◽  
pp. 189-203
Author(s):  
Walter Zenk
Keyword(s):  
Abyssal Currents

scholarly journals Evidence of Bottom-Trapped Currents in the Kuroshio Extension Region

2012 ◽  
Vol 42 (2) ◽  
pp. 321-328 ◽  
Author(s):  
Stuart P. Bishop ◽  
D. Randolph Watts ◽  
Jae-Hun Park ◽  
Nelson G. Hogg
Keyword(s):  
Kuroshio Extension ◽  
Sea Surface ◽  
System Study ◽  
Topographic Features ◽  
Extension System ◽  
Horizontal Length ◽  
Steep Topography ◽  
Abyssal Currents ◽  
The Kuroshio ◽  
Kuroshio Extension Region

Abstract As part of the Kuroshio Extension System Study, observations from five current meter moorings reveal that the abyssal currents are weakly bottom intensified. In the framework of linear quasigeostrophic flow, the best fitted vertical trapping depths range from 8 to 15 km in the absence of steep topography, but one mooring near an isolated seamount exhibited vertical trapping that was more pronounced and energetic with a vertical trapping depth of 5 km. The ratios of current speeds and geostrophic pressure streamfunctions at the sea surface compared to the bottom are 88% in the absence of steep topography, 63% near an isolated seamount, and overall on average 83% of their value at a reference depth of 5300 m. It is hypothesized that weakly depth-dependent eddies impinging upon topographic features introduce to the flow the horizontal length scales of the topography, and these smaller lateral scales are subject to bottom intensification.

Abyssal Currents

2001 ◽  
pp. 15-30
Author(s):  
W. Zenk
Keyword(s):  
Abyssal Currents
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