scholarly journals Assessment of Finescale Parameterizations of Deep Ocean Mixing in the Presence of Geostrophic Current Shear: Results of Microstructure Measurements in the Antarctic Circumpolar Current Region

2019 ◽  
Vol 124 (1) ◽  
pp. 135-153 ◽  
Author(s):  
Anne Takahashi ◽  
Toshiyuki Hibiya
Keyword(s):  
Antarctic Circumpolar Current ◽  
Deep Ocean ◽  
Ocean Mixing ◽  
Geostrophic Current ◽  
Current Region ◽  
Circumpolar Current ◽  
Microstructure Measurements ◽  
The Antarctic

scholarly journals A Microscale View of Mixing and Overturning across the Antarctic Circumpolar Current

2016 ◽  
Vol 46 (1) ◽  
pp. 233-254 ◽  
Author(s):  
Alberto C. Naveira Garabato ◽  
Kurt L. Polzin ◽  
Raffaele Ferrari ◽  
Jan D. Zika ◽  
Alexander Forryan
Keyword(s):  
Antarctic Circumpolar Current ◽  
Large Scale ◽  
Drake Passage ◽  
Small Scale ◽  
Overturning Circulation ◽  
Order Of Magnitude ◽  
Circumpolar Current ◽  
Scale Turbulence ◽  
Microstructure Measurements ◽  
The Antarctic

AbstractThe relative roles of isoneutral stirring by mesoscale eddies and dianeutral stirring by small-scale turbulence in setting the large-scale temperature–salinity relation of the Southern Ocean against the action of the overturning circulation are assessed by analyzing a set of shear and temperature microstructure measurements across Drake Passage in a “triple decomposition” framework. It is shown that a picture of mixing and overturning across a region of the Antarctic Circumpolar Current (ACC) may be constructed from a relatively modest number of microstructure profiles. The rates of isoneutral and dianeutral stirring are found to exhibit distinct, characteristic, and abrupt variations: most notably, a one to two orders of magnitude suppression of isoneutral stirring in the upper kilometer of the ACC frontal jets and an order of magnitude intensification of dianeutral stirring in the subpycnocline and deepest layers of the ACC. These variations balance an overturning circulation with meridional flows of O(1) mm s−1 across the ACC’s mean thermohaline structure. Isoneutral and dianeutral stirring play complementary roles in balancing the overturning, with isoneutral processes dominating in intermediate waters and the Upper Circumpolar Deep Water and dianeutral processes prevailing in lighter and denser layers.

scholarly journals Southern Ocean circulation

2005 ◽  
Vol 32 (2) ◽  
pp. 265-280 ◽  
Author(s):  
Stuart A. Cunningham
Keyword(s):  
Southern Ocean ◽  
Ocean Circulation ◽  
Antarctic Circumpolar Current ◽  
Three Dimensional ◽  
Deep Ocean ◽  
Ocean Basin ◽  
Ocean Dynamics ◽  
Circumpolar Current ◽  
Earth’S Climate ◽  
The Antarctic

The Discovery Investigations of the 1930s provided a compelling description of the main elements of the Southern Ocean circulation. Over the intervening years, this has been extended to include ideas on ocean dynamics based on physical principles. In the modern description, the Southern Ocean has two main circulations that are intimately linked: a zonal (west-east) circumpolar circulation and a meridional (north-south) overturning circulation. The Antarctic Circumpolar Current transports around 140 million cubic metres per second west to east around Antarctica. This zonal circulation connects the Atlantic, Indian and Pacific Oceans, transferring and blending water masses and properties from one ocean basin to another. For the meridional circulation, a key feature is the ascent of waters from depths of around 2,000 metres north of the Antarctic Circumpolar Current to the surface south of the Current. In so doing, this circulation connects deep ocean layers directly to the atmosphere. The circumpolar zonal currents are not stable: meanders grow and separate, creating eddies and these eddies are critical to the dynamics of the Southern Ocean, linking the zonal circumpolar and meridional circulations. As a result of this connection, a global three-dimensional ocean circulation exists in which the Southern Ocean plays a central role in regulating the Earth's climate.

scholarly journals Nonlinear Differential Equations Modeling the Antarctic Circumpolar Current

2021 ◽  
Vol 23 (4) ◽  
Author(s):  
Jifeng Chu ◽  
Kateryna Marynets
Keyword(s):  
Fixed Point ◽  
Differential Equations ◽  
Boundary Conditions ◽  
Topological Degree ◽  
Antarctic Circumpolar Current ◽  
Fixed Point Theorems ◽  
Nonlinear Differential Equations ◽  
Existence Results ◽  
Circumpolar Current ◽  
The Antarctic

AbstractThe aim of this paper is to study one class of nonlinear differential equations, which model the Antarctic circumpolar current. We prove the existence results for such equations related to the geophysical relevant boundary conditions. First, based on the weighted eigenvalues and the theory of topological degree, we study the semilinear case. Secondly, the existence results for the sublinear and superlinear cases are proved by fixed point theorems.

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