Agulhas Ring Heat Content and Transport in the South Atlantic Estimated by Combining Satellite Altimetry and Argo Profiling Floats Data

2020 ◽  
Vol 125 (9) ◽  
Author(s):  
R. Laxenaire ◽  
S. Speich ◽  
A. Stegner
Keyword(s):  
Satellite Altimetry ◽  
Heat Content ◽  
South Atlantic ◽  
The South

The Greenland Clipper: a fast ocean connection between Greenland and the Southern Ocean

2021 ◽  
Author(s):  
Laurits Andreasen ◽  
Markus Jochum ◽  
Anna von der Heydt ◽  
Guido Vettoretti ◽  
Roman Nuterman
Keyword(s):  
Southern Ocean ◽  
Time Lag ◽  
Vertical Mixing ◽  
Heat Content ◽  
South Atlantic ◽  
Heat Fluxes ◽  
Model Parameters ◽  
The South ◽  
High Northern Latitude ◽  
Adjustment Time

<p>The glacial Dansgaard-Oeschger (DO) events are thought to result in a global reorganization of oceanic heat fluxes and heat content.</p><p>DO events originate in the North Atlantic, but are communicated all the way to the pole of the other hemisphere. This interhemispheric coupling is known as the bipolar seesaw. A striking feature of the bipolar seesaw is the ~100 year time lag between the initial onset at high northern latitudes and the following adjustments at high southern latitudes.</p><p>Here, we focus on this time lag.</p><p>Ultimately high southern latitudes are expected to begin their adjustment, when the sea ice margin in the Southern Ocean (SO) shift position due to cooling/warming in the ocean below. But how is the northern signal propagated into the SO, and what processes control the time it takes the SO to change its state?</p><p>We expect the SO adjustment to have four components: Planetary waves, geostrophic adjustments in the Atlantic, vertical mixing and finally heat fluxes from baroclinic eddies in the SO.</p><p>To investigate the relative importance of these components on the adjustment time in the SO, we apply a fresh water perturbation at high northern latitude in an idealized setup of the Atlantic basin and the Southern Ocean using the newly developed OGCM VEROS. We measure the time it takes the model's Southern Ocean to adjust to the perturbation as a function of different model parameters associated with the components mentioned above.</p><p>We find that the adjustment time - which we believe is related to the bipolar seesaw time lag - is dominated by two components. The first is associated with geostrophic adjustment in the South Atlantic, and the second with the eddy heat fluxes in the Southern Ocean. Interestingly we find that in the limit of a high (realistic) eddy transfer (Gent-McWilliams) coefficient, the geostrophic component constitutes the main part of the the adjustment time and quantitatively matches the observed time lag in the bipolar seesaw.</p><p>This make us suggest that the bipolar seesaw time lag could be caused mainly by adjustments in the South Atlantic.</p>

scholarly journals Sea Level Trend and Fronts in the South Atlantic Ocean

Geosciences ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 218
Author(s):  
Laura A. Ruiz-Etcheverry ◽  
Martin Saraceno
Keyword(s):  
Atlantic Ocean ◽  
Sea Level ◽  
Satellite Altimetry ◽  
South Atlantic ◽  
South Atlantic Ocean ◽  
The South ◽  
Steric Height ◽  
Ocean Mass ◽  
Sea Level Trend ◽  
Height Component

The understanding of the physical drivers of sea level trend is crucial on global and regional scales. In particular, little is known about the sea level trend in the South Atlantic Ocean in comparison with other parts of the world. In this work, we computed the South Atlantic mean sea level (SAMSL) trend from 25 years of satellite altimetry data, and we analyzed the contributions of steric height (thermosteric and halosteric components) and ocean mass changes for the period 2005–2016 when all the source data used (Argo, GRACE and satellite altimetry) overlap. The SAMSL trend is 2.65 ± 0.24 mm/yr and is mostly explained by ocean mass trend, which is 2.22 ± 0.21 mm/yr. However, between 50° S–33° S, the steric height component constitutes the main contribution in comparison with the ocean mass component. Within that latitudinal band, three regions with trend values higher than the SAMSL trend are observed when considering 25 years of satellite SLA. In the three regions, a southward displacement of the Subtropical, Subantarctic, and Polar Fronts is observed. The southward shift of the fronts is associated with the strengthening and polar shift of westerly winds and contributes to a clear thermosteric trend that translates to the SLA trend observed in those regions.

Toxigenicity and biogeography of the diatom Pseudo-nitzschia across distinct environmental regimes in the South Atlantic Ocean

2015 ◽  
Vol 526 ◽  
pp. 67-87 ◽  
Author(s):  
ML Guannel ◽  
D Haring ◽  
MJ Twiner ◽  
Z Wang ◽  
AE Noble ◽  
...  
Keyword(s):  
Atlantic Ocean ◽  
South Atlantic ◽  
South Atlantic Ocean ◽  
The South ◽  
Environmental Regimes

POLITICAL AND STRATEGIC COORDINATION AND COOPERATION FOR DEVELOPMENT: THE CASES OF ZPCSA AND GGC

2016 ◽  
Vol 31 (2) ◽  
pp. 19-36
Author(s):  
Paulo Fagundes Visentini ◽  
Analúcia Danilevicz Pereira
Keyword(s):  
South Atlantic ◽  
Strategic Orientation ◽  
International Affairs ◽  
The South ◽  
Strategic Issues ◽  
Strategic Coordination ◽  
Regional Order ◽  
Energy Products ◽  
A Site ◽  
Political Economic

The creation of the Zone of Peace and Cooperation of the South Atlantic (ZPCSA) in 1986 and the Gulf of Guinea Commission (GGC) in 2001 was about changes in the distribution of world power. This article argues that though they emerged at different times, their strategic orientation converges in a number of areas related to the significant interests in the South Atlantic as an area of stability in the region to be marked by strong political, economic and military ties. They also converge on the ideal for development, security and greater projection of power and influence in international affairs. The South Atlantic being a route of passage and trade, as a means of access and flow of energy products, the region became a site for new calculations of regional strategic powers about world affairs. The article also argues that ZPCSA and GGC are therefore crucial for the regional order and the development of higher capacities for cooperation on strategic issues. The actual point of convergence extends to ensuring the sovereignty through dialogue between the states in the region that are involved.

Observed seasonal regimes of North-South Atlantic Ocean interbasin exchange

2019 ◽  
Author(s):  
Hamed D. Ibrahim
Keyword(s):  
North Atlantic ◽  
Climate Models ◽  
South Atlantic ◽  
Meridional Overturning Circulation ◽  
Volume Flux ◽  
The South ◽  
The North ◽  
Basin Scale ◽  
Interbasin Exchange ◽  
North And South

North and South Atlantic lateral volume exchange is a key component of the Atlantic Meridional Overturning Circulation (AMOC) embedded in Earth’s climate. Northward AMOC heat transport within this exchange mitigates the large heat loss to the atmosphere in the northern North Atlantic. Because of inadequate climate data, observational basin-scale studies of net interbasin exchange between the North and South Atlantic have been limited. Here ten independent climate datasets, five satellite-derived and five analyses, are synthesized to show that North and South Atlantic climatological net lateral volume exchange is partitioned into two seasonal regimes. From late-May to late-November, net lateral volume flux is from the North to the South Atlantic; whereas from late-November to late-May, net lateral volume flux is from the South to the North Atlantic. This climatological characterization offers a framework for assessing seasonal variations in these basins and provides a constraint for climate models that simulate AMOC dynamics.

MODELING THE SOUTH ATLANTIC OCEAN FROM MEDIUM TO HIGH RESOLUTION

2014 ◽  
Vol 31 (2) ◽  
Author(s):  
Mariela Gabioux ◽  
Vladimir Santos da Costa ◽  
Joao Marcos Azevedo Correia de Souza ◽  
Bruna Faria de Oliveira ◽  
Afonso De Moraes Paiva
Keyword(s):  
High Resolution ◽  
Atlantic Ocean ◽  
Large Scale ◽  
South Atlantic ◽  
Surface Relaxation ◽  
The South ◽  
Small Surface ◽  
Basic Model ◽  
Basic Set ◽  
Set Up

Results of the basic model configuration of the REMO project, a Brazilian approach towards operational oceanography, are discussed. This configuration consists basically of a high-resolution eddy-resolving, 1/12 degree model for the Metarea V, nested in a medium-resolution eddy-permitting, 1/4 degree model of the Atlantic Ocean. These simulations performed with HYCOM model, aim for: a) creating a basic set-up for implementation of assimilation techniques leading to ocean prediction; b) the development of hydrodynamics bases for environmental studies; c) providing boundary conditions for regional domains with increased resolution. The 1/4 degree simulation was able to simulate realistic equatorial and south Atlantic large scale circulation, both the wind-driven and the thermohaline components. The high resolution simulation was able to generate mesoscale and represent well the variability pattern within the Metarea V domain. The BC mean transport values were well represented in the southwestern region (between Vitória-Trinidade sea mount and 29S), in contrast to higher latitudes (higher than 30S) where it was slightly underestimated. Important issues for the simulation of the South Atlantic with high resolution are discussed, like the ideal place for boundaries, improvements in the bathymetric representation and the control of bias SST, by the introducing of a small surface relaxation. In order to make a preliminary assessment of the model behavior when submitted to data assimilation, the Cooper & Haines (1996) method was used to extrapolate SSH anomalies fields to deeper layers every 7 days, with encouraging results.

SUBMARINE GROUNDWATER DISCHARGE TO THE CONTINENTAL SHELF IN THE SOUTH ATLANTIC BIGHT

2018 ◽  
Author(s):  
Camaron M. George ◽  
◽  
Alicia Wilson ◽  
Willard Moore ◽  
Scott White ◽  
...  
Keyword(s):  
Continental Shelf ◽  
Submarine Groundwater Discharge ◽  
Groundwater Discharge ◽  
South Atlantic ◽  
South Atlantic Bight ◽  
The South ◽  
Submarine Groundwater

USING NEODYMIUM ISOTOPES TO DECIPHER COMPLEX CIRCULATION PATTERNS IN THE SOUTH ATLANTIC AT THE END OF THE CRETACEOUS

2020 ◽  
Author(s):  
Shannon J. Haynes ◽  
◽  
Kenneth G. MacLeod ◽  
Jean-Baptiste Ladant ◽  
Christopher J. Poulsen ◽  
...  
Keyword(s):  
South Atlantic ◽  
The South ◽  
Neodymium Isotopes ◽  
Circulation Patterns
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