Comparing Models of Trophic Flows in the Northern and Southern Benguela Upwelling Systems During the 1980s

1999 ◽  
Author(s):  
L.J. Shannnon ◽  
A. Jarre-Treichmann
Keyword(s):  
Benguela Upwelling

A Holocene Marine Climate Record in Mollusc Shells from the Southwest African Coast

1992 ◽  
Vol 38 (3) ◽  
pp. 379-385 ◽  
Author(s):  
Anne L. Cohen ◽  
John E. Parkington ◽  
Geoff B. Brundrit ◽  
Nikolaas J. van der Merwe
Keyword(s):  
Late Quaternary ◽  
Climatic Variability ◽  
Temperature Changes ◽  
Climate Record ◽  
Benguela Upwelling ◽  
Isotope Record ◽  
History Of ◽  
Glacial Expansion ◽  
Sediment Layers ◽  
Marine Climate

AbstractDetails of short-term climatic variability are often lost from marine sediments through bioturbation in the upper, aerobic sediment layers. Alternatively, a high-resolution and dated record of climatic events may be obtained using material preserved in archaeological deposits. The Holocene history of the southern Benguela upwelling regime has been constructed from the oxygen isotope and mineral analysis of midden shells. Three discrete episodes of significant isotope enrichment corresponded to periods of glacial expansion in the northern hemisphere. Significant changes in shell mineralogy, which is a response to sea-surface temperatures, were also recorded. The timing and duration of these changes approximated those in the isotope record and may provide a link between events affecting the subcontinent and global temperature changes of the late Quaternary.

Seasonal and interannual phytoplankton dynamics and forcing mechanisms in the Northern Benguela upwelling system

2016 ◽  
Vol 157 ◽  
pp. 124-134 ◽  
Author(s):  
Deon C. Louw ◽  
Anja K. van der Plas ◽  
Volker Mohrholz ◽  
Norbert Wasmund ◽  
Tim Junker ◽  
...  
Keyword(s):  
Phytoplankton Dynamics ◽  
Upwelling System ◽  
Benguela Upwelling ◽  
Forcing Mechanisms

scholarly journals The Impact of Agulhas Leakage on the Central Water Masses in the Benguela Upwelling System From A High‐Resolution Ocean Simulation

2018 ◽  
Vol 123 (12) ◽  
pp. 9416-9428 ◽  
Author(s):  
Nele Tim ◽  
Eduardo Zorita ◽  
Franziska U. Schwarzkopf ◽  
Siren Rühs ◽  
Kay‐Christian Emeis ◽  
...  
Keyword(s):  
High Resolution ◽  
Water Masses ◽  
Upwelling System ◽  
Benguela Upwelling ◽  
The Impact ◽  
Ocean Simulation

scholarly journals N2O Emissions From the Northern Benguela Upwelling System

2019 ◽  
Vol 46 (6) ◽  
pp. 3317-3326 ◽  
Author(s):  
D. L. Arévalo‐Martínez ◽  
T. Steinhoff ◽  
P. Brandt ◽  
A. Körtzinger ◽  
T. Lamont ◽  
...  
Keyword(s):  
N2o Emissions ◽  
Upwelling System ◽  
Benguela Upwelling

The Impacts of Inter–El Niño Variability on the Tropical Atlantic and Northeast Brazil Climate

2011 ◽  
Vol 24 (13) ◽  
pp. 3402-3422 ◽  
Author(s):  
Regina R. Rodrigues ◽  
Reindert J. Haarsma ◽  
Edmo J. D. Campos ◽  
Tércio Ambrizzi
Keyword(s):  
El Niño ◽  
El Nino ◽  
South Atlantic ◽  
Ocean Dynamics ◽  
Boreal Winter ◽  
Cold Tongue ◽  
Equatorial Atlantic ◽  
Boreal Spring ◽  
Benguela Upwelling ◽  
Sst Anomalies

Abstract In this study, observations and numerical simulations are used to investigate how different El Niño events affect the development of SST anomalies in the Atlantic and how this relates to the Brazilian northeast (NE) precipitation. The results show that different types of El Niño have different impacts on the SST anomalies of the equatorial and tropical South Atlantic but a similar SST response in the tropical North Atlantic. Strong and long (weak and short) El Niños with the main heating source located in the eastern (central) Pacific generate cold (warm) anomalies in the cold tongue and Benguela upwelling regions during boreal winter and spring. When the SST anomalies in the eastern equatorial and tropical South Atlantic are cold (warm), the meridional SST gradient across the equator is positive (negative) and the ITCZ is not allowed (allowed) to move southward during the boreal spring; as a consequence, the precipitation is below (above) the average over the NE. Thus, strong and long (weak and short) El Niños are followed by dry (wet) conditions in the NE. During strong and long El Niños, changes in the Walker circulation over the Atlantic and in the Pacific–South Atlantic (PSA) wave train cause easterly wind anomalies in the western equatorial Atlantic, which in turn activate the Bjerknes mechanism, establishing the cold tongue in boreal spring and summer. These easterly anomalies are also responsible for the Benguela upwelling. During short and weak El Niños, westerly wind anomalies are present in the western equatorial Atlantic accompanied by warm anomalies in the eastern equatorial and tropical South Atlantic; a positive phase of the South Atlantic dipole develops during boreal winter. The simulations highlight the importance of ocean dynamics in establishing the correct slope of the equatorial thermocline and SST anomalies, which in turn determine the correct rainfall response over the NE.

scholarly journals Contrasting wind patterns and toxigenic phytoplankton in the southern Benguela upwelling system

2007 ◽  
Vol 348 ◽  
pp. 19-31 ◽  
Author(s):  
A Fawcett ◽  
GC Pitcher ◽  
S Bernard ◽  
AD Cembella ◽  
RM Kudela
Keyword(s):  
Upwelling System ◽  
Benguela Upwelling ◽  
Wind Patterns

scholarly journals On the changes in the sea surface temperature in the Benguela upwelling region. Part 1: season cycle

2019 ◽  
pp. 33-44
Author(s):  
A. B. Polonsky ◽  
A. N. Serebrennikov
Keyword(s):  
Surface Temperature ◽  
Seasonal Variability ◽  
Surface Wind ◽  
Water Layer ◽  
Hydrodynamic Characteristics ◽  
Entire Area ◽  
Near Surface ◽  
Sea Level Anomalies ◽  
Benguela Upwelling ◽  
Upwelling Index

Based on daily ocean surface temperature values for 1982–2017, near-surface wind for 1988–2017. and sea level anomalies for 1993–2017, obtained from satellite data, the seasonal variability of the hydrodynamic characteristics of the upper water layer in the vicinity of the Benguela upwelling is investigated. It is shown that the thermal upwelling index averaged over the entire area with lower temperature values does not give a correct idea on the seasonal course of the water lifting rate in the upwelling zone due to the significant horizontal advection of waters of upwelling origin. The seasonal variations of the vertical velocity of wind origin in the Benguela upwelling zone are characterized by the presence of two extremes from October to March, which is manifested in the predominance of the semiannual harmonic. At the same time, the thermal upwelling index in the zone of distribution of upwelling waters is subject to seasonal variability with an annual period.

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