Evidence for interannual and interdecadal climate variability in the South Atlantic

1996 ◽  
Vol 23 (19) ◽  
pp. 2673-2676 ◽  
Author(s):  
Silvia A. Venegas ◽  
Lawrence A. Mysak ◽  
David N. Straub
Keyword(s):  
Climate Variability ◽  
South Atlantic ◽  
The South ◽  
Interdecadal Climate Variability

scholarly journals Correction to “Evidence for interannual and interdecadal climate variability in the South Atlantic”

1996 ◽  
Vol 23 (23) ◽  
pp. 3425-3425
Author(s):  
Silvia A. Venegas ◽  
Lawrence A. Mysak ◽  
David N. Straub
Keyword(s):  
Climate Variability ◽  
South Atlantic ◽  
The South ◽  
Interdecadal Climate Variability

scholarly journals Potential Sources of Decadal Climate Variability over Southern Africa

2015 ◽  
Vol 28 (22) ◽  
pp. 8695-8709 ◽  
Author(s):  
Yushi Morioka ◽  
Francois Engelbrecht ◽  
Swadhin K. Behera
Keyword(s):  
Indian Ocean ◽  
Climate Variability ◽  
Southern Africa ◽  
South Atlantic ◽  
Decadal Climate Variability ◽  
The South ◽  
Sst Anomaly ◽  
Decadal Climate ◽  
Southwestern Indian Ocean ◽  
Sst Anomalies

Abstract Potential sources of decadal climate variability over southern Africa are examined by conducting in-depth analysis of available datasets and coupled general circulation model (CGCM) experiments. The observational data in recent decades show a bidecadal variability noticeable in the southern African rainfall with its positive phase of peak during 1999/2000. It is found that the rainfall variability is related to anomalous moisture advection from the southwestern Indian Ocean, where the anomalous sea level pressure (SLP) develops. The SLP anomaly is accompanied by anomalous sea surface temperature (SST). Both SLP and SST anomalies slowly propagate eastward from the South Atlantic to the southwestern Indian Ocean. The analysis of mixed layer temperature tendency reveals that the SST anomaly in the southwestern Indian Ocean is mainly due to eastward advection of the SST anomaly by the Antarctic Circumpolar Current. The eastward propagation of SLP and SST anomalies are also confirmed in the 270-yr outputs of the CGCM control experiment. However, in a sensitivity experiment where the SST anomalies in the South Atlantic are suppressed by the model climatology, the eastward propagation of the SLP anomaly from the South Atlantic disappears. These results suggest that the local air–sea coupling in the South Atlantic may be important for the eastward propagation of the SLP anomaly from the South Atlantic to the southwestern Indian Ocean. Although remote influences from the tropical Pacific and Antarctica were widely discussed, this study provides new evidence for the potential role of local air–sea coupling in the South Atlantic for the decadal climate variability over southern Africa.

Investigating the volcanic impacts on Tropical South Atlantic modes of variability for the Historical period using the IPSL-CM6-LR Large Ensemble and INPE-BESM

2020 ◽  
Author(s):  
Eduardo Lobo Lopes ◽  
Ilana Elazari Klein Coaracy Wainer ◽  
Myriam Khodri
Keyword(s):  
Climate Variability ◽  
Atlantic Ocean ◽  
Volcanic Eruptions ◽  
Ocean Basin ◽  
South Atlantic ◽  
South Atlantic Ocean ◽  
Climate Indices ◽  
Historical Period ◽  
The South ◽  
Large Ensemble

<p>In this study we investigate the the South Atlantic Ocean response to large tropical volcanic eruptions for the historial periods. In particular, we analyse the changes in the coupling of the ocean and the atmosphere over that ocean basin triggered by changes in the amount of incoming shortwave radiation.</p><p>The analysis consists of averaging the response of the five biggest eruptions in the last 200 years, namely, Krakatoa (1883), Santa Maria (1902), Agung (1963), El Chichón (1982) and Pinatubo (1991), represented by the IPSL-CMP6-LR Large Ensemble, from the Institut Pierre Simon Laplace, and the BESM-CMIP6, from INPE-CPTEC. We perform the same analysis on reanalysis products as well, such as the HadISST and NOAA's ERSSTv5.</p><p>In order to capture the interannual change in the climate variability, we use two climate indices that assess the coupling of ocean and atmosphere over this timescale, namely, the Atlantic Meridional Mode (AMM) and the South Atlantic Subtropical Dipole (SASD). We compute their time series from the model output and calculate their regression to the SST and precipitation fields.</p><p>Such analysis should yield more insights on how the interaction between the ocean and the atmosphere responds to external forcings, providing a better understanding of the processes that control the climate variability over the South Atlantic Ocean basin.</p>

Are marine heatwaves increasing the likelihood of terrestrial heatwaves? 

2021 ◽  
Author(s):  
Charuni Pathmeswaran ◽  
Sarah Perkins-Kirkpatrick ◽  
Alex Sen Gupta ◽  
Melissa Hart
Keyword(s):  
Statistical Analysis ◽  
South America ◽  
Climate Variability ◽  
Large Scale ◽  
South Atlantic ◽  
Temperature Data ◽  
The South ◽  
Coastal Marine ◽  
Synoptic Conditions ◽  
Modes Of Climate Variability

<p>Despite numerous studies that have examined terrestrial or marine heatwaves independently, little work has been done investigating any possible association between the two. Examination of a limited number of past events suggests that co-occurring terrestrial and marine heatwaves may have common drivers, or may interact with each other. For example, a recent study<sup>1</sup> identified common remote drivers behind the major marine heatwave that developed in the South Atlantic during the summer of 2013/14 and terrestrial heatwaves over South America. Co-occurring events could also potentially interact via local land-sea interactions, thereby altering the likelihood of these co-occurring events. This study will explore possible links between adjacent coastal marine and terrestrial heatwaves. We will investigate the likelihood of co-occurrence of terrestrial and marine heatwaves, using statistical analysis of observational temperature data. We will also investigate the mechanisms driving co-occurring events, including the local fluxes, synoptic conditions, and links to large scale modes of climate variability</p>

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.

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