Southern Africa and the South Atlantic

1986 ◽  
pp. 138-146
Author(s):  
Neil MacFarlane
Keyword(s):  
Southern Africa ◽  
South Atlantic ◽  
The South

scholarly journals A weather regime characterisation of winter biomass aerosol transport from southern Africa

2021 ◽  
Author(s):  
Marco Gaetani ◽  
Benjamin Pohl ◽  
Maria del Carmen Alvarez Castro ◽  
Cyrille Flamant ◽  
Paola Formenti
Keyword(s):  
Spatial Distribution ◽  
Southern Africa ◽  
Forest Fires ◽  
South Atlantic ◽  
Austral Winter ◽  
The South ◽  
Predictive Tool ◽  
Weather Regime ◽  
Synoptic Variability

Abstract. During austral winter, a compact low cloud deck over South Atlantic contrasts with clear sky over southern Africa, where forest fires triggered by dry conditions emit large amount of biomass burning aerosols (BBA) in the free troposphere. Most of the BBA burden crosses South Atlantic embedded in the tropical easterly flow. However, midlatitude synoptic disturbances can deflect part of the aerosol from the main transport path towards southern extratropics. In this study, a characterisation of the synoptic variability controlling the spatial distribution of BBA in southern Africa and South Atlantic during austral winter (August to October) is presented. By analysing atmospheric circulation data from reanalysis products, a 6-class weather regime (WR) classification of the region is constructed. The classification reveals that the synoptic variability is composed by four WRs representing disturbances travelling at midlatitudes, and two WRs accounting for pressure anomalies in the South Atlantic. The WR classification is then successfully used to characterise the aerosol spatial distribution in the region in the period 2003–2017, in both reanalysis products and station data. Results show that the BBA transport towards southern extratropics is controlled by weather regimes associated with midlatitude synoptic disturbances. In particular, depending on the relative position of the pressure anomalies along the midlatitude westerly flow, the BBA transport is deflected from the main tropical route towards southern Africa or the South Atlantic. This paper presents the first objective classification of the winter synoptic circulation over South Atlantic and southern Africa. The classification shows skills in characterising the BBA transport, indicating the potential for using it as a diagnostic/predictive tool for aerosol dynamics, which is a key component for the full understanding and modelling of the complex radiation-aerosol-cloud interactions controlling the atmospheric radiative budget in the region.

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.

scholarly journals New Archeomagnetic Directional Records From Iron Age Southern Africa (ca. 425–1550 CE) and Implications for the South Atlantic Anomaly

2018 ◽  
Vol 45 (3) ◽  
pp. 1361-1369 ◽  
Author(s):  
Vincent J. Hare ◽  
John A. Tarduno ◽  
Thomas Huffman ◽  
Michael Watkeys ◽  
Phenyo C. Thebe ◽  
...  
Keyword(s):  
Iron Age ◽  
Southern Africa ◽  
South Atlantic ◽  
The South ◽  
South Atlantic Anomaly

The African Slave Trade and the Construction of the Iberian Atlantic

2017 ◽  
Author(s):  
Luiz Felipe de Alencastro
Keyword(s):  
Eighteenth Century ◽  
Latin America ◽  
South America ◽  
Southern Africa ◽  
Slave Trade ◽  
South Atlantic ◽  
The South ◽  
African Slave ◽  
History Of

Scholarly studies of the colonization of the Americas—especially of Latin America—have tended to minimize the role played by Africans and the African slave trade, treating the history of conquest and colonialism as a story of inevitable European domination of the hemisphere. However, from the sixteenth through the eighteenth century, colonialism in the Americas depended upon the exportation of slaves from Africa, a massive undertaking that was supported not only by Iberian Royal families but also by convoluted ideological and theological justifications elaborated by legal and religious scholars. During this period, Portugal dominated the slave trade, raiding its colonies in Southern Africa to supply its plantations (many run by Jesuits) in South America. In this sense, the story of the South Atlantic is a story of encounters and exchanges between Africa and the Americas.

scholarly journals A weather regime characterisation of winter biomass aerosol transport from southern Africa

2021 ◽  
Vol 21 (21) ◽  
pp. 16575-16591
Author(s):  
Marco Gaetani ◽  
Benjamin Pohl ◽  
Maria del Carmen Alvarez Castro ◽  
Cyrille Flamant ◽  
Paola Formenti
Keyword(s):  
Spatial Distribution ◽  
Southern Africa ◽  
Forest Fires ◽  
South Atlantic ◽  
Austral Winter ◽  
The South ◽  
Predictive Tool ◽  
Weather Regime ◽  
Synoptic Variability

Abstract. During austral winter, a compact low cloud deck over the South Atlantic contrasts with clear sky over southern Africa, where forest fires triggered by dry conditions emit large amounts of biomass burning aerosols (BBAs) in the free troposphere. Most of the BBA burden crosses the South Atlantic embedded in the tropical easterly flow. However, midlatitude synoptic disturbances can deflect part of the aerosol from the main transport path towards southern extratropics. In this study, the first objective classification of the synoptic variability controlling the spatial distribution of BBA in southern Africa and the South Atlantic during austral winter (August to October) is presented. By analysing atmospheric circulation data from reanalysis products, a six-class weather regime (WR) classification of the region is constructed. The classification reveals that the synoptic variability is composed of four WRs, representing disturbances travelling at midlatitudes, and two WRs accounting for pressure anomalies in the South Atlantic. The WR classification is then successfully used to characterise the aerosol spatial distribution in the region in the period 2003–2017, in both reanalysis products and station data. Results show that the BBA transport towards southern extratropics is controlled by weather regimes associated with midlatitude synoptic disturbances. In particular, depending on the relative position of the pressure anomalies along the midlatitude westerly flow, the BBA transport is deflected from the main tropical route towards southern Africa or the South Atlantic. Moreover, the WRs accounting for midlatitude disturbances show organised transition sequences, which allow one to illustrate the evolution of the BBA northerly transport across the region in the context of a wave pattern. The skill in characterising the BBA transport shown by the WR classification indicates the potential for using it as a diagnostic/predictive tool for the aerosol dynamics, which is a key component for the full understanding and modelling of the complex radiation–aerosol–cloud interactions controlling the atmospheric radiative budget in the region.

AN ARCHEOMAGNETIC RECORD FROM SOUTHERN AFRICA AND ITS BEARING ON THE HISTORY OF THE SOUTH ATLANTIC ANOMALY

2017 ◽  
Author(s):  
John A. Tarduno ◽  
◽  
Vincent Hare ◽  
Vincent Hare ◽  
Vincent Hare ◽  
...  
Keyword(s):  
Southern Africa ◽  
South Atlantic ◽  
The South ◽  
South Atlantic Anomaly ◽  
History Of ◽  
History Of The South
Sign in / Sign up

Export Citation Format

Share Document