Article
Engineering, Environmental
Daniele de A. Miranda, Juliana Leonel, Jonathan P. Benskin, Jana Johansson, Vanessa Hatje
Summary: The study found that the distribution of PFAS in the Western Tropical Atlantic Ocean varied with depth and longitude sectors. PFAS mainly existed in the form of perfluoroalkyl carboxylic acids, and the origin of different water masses was also an important factor affecting PFAS concentrations and profiles.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2021)
Article
Meteorology & Atmospheric Sciences
Riccardo Farneti, Alessandro Stiz, John B. Ssebandeke
Summary: State-of-the-art climate models show biases in simulating sea surface temperatures in eastern boundary upwelling systems, with the largest bias observed in the southeastern tropical Atlantic. High-resolution and ocean-forced models have shown improvement in reducing these biases, but further development of model physics schemes is necessary.
NPJ CLIMATE AND ATMOSPHERIC SCIENCE
(2022)
Article
Environmental Sciences
Te Liu, Stephan Krisch, Ruifang C. Xie, Mark J. Hopwood, Marcus Dengler, Eric P. Achterberg
Summary: The Benguela Upwelling System in the eastern South Atlantic Ocean is characterized by high nutrient concentrations and trace metals, which primarily come from benthic sources near the shelf and off-shelf transfer. Under future conditions of increasing ocean deoxygenation, these fluxes may increase further, potentially leading to more extensive regional limitation of primary production by fixed nitrogen availability.
GLOBAL BIOGEOCHEMICAL CYCLES
(2022)
Article
Meteorology & Atmospheric Sciences
Jaison Kurian, Pin Li, Ping Chang, Christina M. Patricola, Justin Small
Summary: The current generation of coupled ocean-atmosphere climate models faces challenges in accurately simulating the warm bias in the Southeast Tropical Atlantic region, primarily due to inaccuracies in near-coastal winds and unique ocean circulation features. Ocean model resolution and the strength and structure of the Benguela low-level coastal jet are found to be crucial factors in reducing the warm SST bias in SETA.
Article
Oceanography
Elisa Lovecchio, Stephanie Henson, Filipa Carvalho, Nathan Briggs
Summary: This study investigates the variability and drivers of low-oxygen events in the offshore northern Benguela Upwelling System (BenUS) using high-resolution glider data. The results show that oxygen concentrations are determined by the alternation of low-oxygen Angola-derived water and oxygenated water from the south. Hypoxic events are more persistent at certain depths and more sporadic at shallower depths. The findings emphasize the need for long-term and high-resolution measurements and studies focusing on future changes in both tropical oxygen levels and lateral fluxes in this region.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2022)
Article
Meteorology & Atmospheric Sciences
Arthur Prigent, Rodrigue Anicet Imbol Koungue, Joke F. Luebbecke, Peter Brandt, Jan Harlass, Mojib Latif
Summary: Research using the global climate model FOCI indicates that the interannual sea surface temperature variability in the southeastern tropical Atlantic will decrease significantly in response to increasing greenhouse gas concentrations, especially in the Coastal Angola Benguela Area. Under the worst-case scenario, the reduction in variability is linked to weakened thermocline feedback and changes in the mean vertical temperature gradient. Despite improvements in the model, a significant sea surface temperature bias remains, potentially impacting the results.
Article
Meteorology & Atmospheric Sciences
Jorge Lopez-Parages, Laurent Terray
Summary: In this study, the role of the ENSO teleconnection with the tropical North Atlantic sea surface temperatures in boreal spring is analyzed. It is found that the Atlantic meridional mode plays a significant role in this teleconnection. The study also highlights the importance of coastal upwelling off northwest Africa in triggering this teleconnection. Additionally, it is shown that high-resolution models are more sensitive to surface wind errors, but do not necessarily improve the reliability or predictability of the TNA SST response to ENSO.
JOURNAL OF CLIMATE
(2022)
Article
Oceanography
T. B. Mashifane, A. Bourbonnais, S. E. Fawcett
Summary: Using a coupled physical-biogeochemical model and new observations, this study investigates the dynamics of nitrous oxide (N2O) in St Helena Bay, a region in the southern Benguela upwelling system. The results show that significant N2O production occurs in nearshore waters, and this N2O is advected equatorward at a high rate. By contrast, low N2O concentrations are found in the poleward undercurrent on the shelf slope. The study also calculates the N2O flux in the entire SBUS region and finds that it represents 0.1% of the estimated global ocean annual flux.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2022)
Article
Geosciences, Multidisciplinary
Franz Philip Tuchen, Renellys C. Perez, Gregory R. Foltz, Peter Brandt, Rick Lumpkin
Summary: Tropical Instability Waves (TIWs) are the dominant source of intraseasonal variability in the central equatorial Atlantic and play a crucial role in redistributing heat in the upper ocean. A study using multidecadal records of various oceanic variables has shown a long-term intensification of intraseasonal variability, particularly due to increased TIW activity. This pattern is driven by enhanced barotropic energy conversion from the covariance of horizontal current fluctuations.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Oceanography
Moagabo Natalie Ragoasha, Steven Herbette, Jennifer Veitch, Gildas Cambon, Chris J. C. Reason, Claude Roy
Summary: A regional ocean model and Lagrangian particle release experiments were used to investigate the impact of wind-driven coastal circulation and mesoscale variability on transport success in the southern Benguela. The study found that the inter-annual variability of transport success is influenced by both coastal circulation and offshore Ekman transport, as well as mesoscale eddies near the shelf edge.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2022)
Article
Environmental Sciences
Erik van Sebille, Erik Zettler, Nicolas Wienders, Linda Amaral-Zettler, Shane Elipot, Rick Lumpkin
Summary: An analysis of two types of surface drifters deployed in the Tropical Atlantic Ocean revealed that undrogued drifters separate more slowly than drogued drifters, and are more likely to enter the Caribbean Sea. The study also found that a novel ocean currents product did not clearly simulate the drifters, highlighting the need for further improvements in hydrodynamic models for Sargassum drift forecasting in the region.
FRONTIERS IN MARINE SCIENCE
(2021)
Article
Meteorology & Atmospheric Sciences
Leishan Jiang, Tim Li
Summary: The tropical Atlantic sea surface temperature anomaly is influenced by two dominant modes: basin-warming mode and meridional dipole mode, affecting the following winter's climate. The basin-warming mode induces a La Nina through Kelvin wave response and wind-evaporation-SST-convection feedback, while the dipole mode has little impact. Studies show that the differences in these modes play a role in the development of ENSO events in the Pacific Ocean.
JOURNAL OF CLIMATE
(2021)
Article
Environmental Sciences
Marisa Roch, Peter Brandt, Sunke Schmidtko, Filomena Vaz Velho, Marek Ostrowski
Summary: Observations from the Argo float array show a warming and freshening trend in the upper mixed layer of the southeastern tropical Atlantic Ocean, leading to increased upper-ocean stratification. Changes in wind stress and weakened coastal upwelling may explain the southward spread of tropical surface waters in the region.
FRONTIERS IN MARINE SCIENCE
(2021)
Article
Environmental Sciences
Tim Rixen, Niko Lahajnar, Tarron Lamont, Rolf Koppelmann, Bettina Martin, Justus E. E. van Beusekom, Claire Siddiqui, Keshnee Pillay, Luisa Meiritz
Summary: The study shows that a topographically steered nutrient trapping zone develops during the main upwelling season in the southern Benguela Upwelling System, enhancing productivity but potentially decreasing oxygen concentrations. At the end of the upwelling season, the front separating the trapped and open shelf waters weakens or collapses due to upwelling cessation and changing current regimes.
FRONTIERS IN MARINE SCIENCE
(2021)
Article
Environmental Sciences
A. P. Dansie, D. S. G. Thomas, G. F. S. Wiggs, M. C. Baddock, I. Ashpole
Summary: Ocean-based photosynthesis plays a significant role in global primary production. However, the productivity rates in the oceans vary greatly due to the response of phytoplankton to nutrient availability. This study focuses on the relationship between iron-rich dust plumes from Namibia's ephemeral river valleys and phytoplankton blooms in the Benguela Upwelling System off southwest Africa. The results show a fast chlorophyllic response to observed dust emissions and a correlation between terrestrial dust concentrations and offshore phytoplankton concentrations.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Geosciences, Multidisciplinary
Marie-Lou Bachelery, Serena Illig, Mathieu Rouault
JOURNAL OF MARINE SYSTEMS
(2020)
Review
Ecology
Z. Sohou, V Kone, Y. C. Da-Allada, S. Djakoure, B. Bourles, V Racape, G. Degbe, C. Adje
REGIONAL STUDIES IN MARINE SCIENCE
(2020)
Article
Oceanography
Ramilla Assuncao, Alex C. Silva, Amedee Roy, Bernard Bourles, Carlos Henrique S. Silva, Jean-Francois Ternon, Moacyr Araujo, Arnaud Bertrand
PROGRESS IN OCEANOGRAPHY
(2020)
Article
Environmental Sciences
Annie P. S. Wong, Susan E. Wijffels, Stephen C. Riser, Sylvie Pouliquen, Shigeki Hosoda, Dean Roemmich, John Gilson, Gregory C. Johnson, Kim Martini, David J. Murphy, Megan Scanderbeg, T. V. S. Udaya Bhaskar, Justin J. H. Buck, Frederic Merceur, Thierry Carval, Guillaume Maze, Cecile Cabanes, Xavier Andre, Noe Poffa, Igor Yashayaev, Paul M. Barker, Stephanie Guinehut, Mathieu Belbeoch, Mark Ignaszewski, Molly O'Neil Baringer, Claudia Schmid, John M. Lyman, Kristene E. McTaggart, Sarah G. Purkey, Nathalie Zilberman, Matthew B. Alkire, Dana Swift, W. Brechner Owens, Steven R. Jayne, Cora Hersh, Pelle Robbins, Deb West-Mack, Frank Bahr, Sachiko Yoshida, Philip J. H. Sutton, Romain Cancouet, Christine Coatanoan, Delphine Dobbler, Andrea Garcia Juan, Jerome Gourrion, Nicolas Kolodziejczyk, Vincent Bernard, Bernard Bourles, Herve Claustre, Fabrizio D'Ortenzio, Serge Le Reste, Pierre-Yve Le Traon, Jean-Philippe Rannou, Carole Saout-Grit, Sabrina Speich, Virginie Thierry, Nathalie Verbrugge, Ingrid M. Angel-Benavides, Birgit Klein, Giulio Notarstefano, Pierre-Marie Poulain, Pedro Velez-Belchi, Toshio Suga, Kentaro Ando, Naoto Iwasaska, Taiyo Kobayashi, Shuhei Masuda, Eitarou Oka, Kanako Sato, Tomoaki Nakamura, Katsunari Sato, Yasushi Takatsuki, Takashi Yoshida, Rebecca Cowley, Jenny L. Lovell, Peter R. Oke, Esmee M. van Wijk, Fiona Carse, Matthew Donnelly, W. John Gould, Katie Gowers, Brian A. King, Stephen G. Loch, Mary Mowat, Jon Turton, E. Pattabhi Rama Rao, M. Ravichandran, Howard J. Freeland, Isabelle Gaboury, Denis Gilbert, Blair J. W. Greenan, Mathieu Ouellet, Tetjana Ross, Anh Tran, Mingmei Dong, Zenghong Liu, Jianping Xu, KiRyong Kang, HyeongJun Jo, Sung-Dae Kim, Hyuk-Min Park
FRONTIERS IN MARINE SCIENCE
(2020)
Article
Marine & Freshwater Biology
T. Toolsee, T. Lamont, M. Rouault, I Ansorge
Summary: This study provides the first seasonal characterization of surface hydrography at the Prince Edward Islands, with findings of differences in sea surface temperature, wind speed, currents, geostrophic currents, and Ekman currents at different locations around the islands. The study also highlights the relationship between geostrophic currents and wind speed, and the islands acting as a barrier to the flow downstream. This seasonal characterization serves as a baseline for assessing interannual/decadal variability and future changes in these parameters.
AFRICAN JOURNAL OF MARINE SCIENCE
(2021)
Article
Environmental Sciences
Cristina Serena Russo, Tarron Lamont, Marjolaine Krug
Summary: This study introduces an improved method (LACCE) to accurately identify the core and edges of the Agulhas Current, compared with previous algorithms. The results demonstrate the successful application of LACCE in monitoring changes in current position and reflection spatial-temporal variability. The study also confirms seasonal variations in the reflection position and identifies the triggering mechanism for early reflections.
REMOTE SENSING OF ENVIRONMENT
(2021)
Article
Environmental Sciences
Matthew Carr, Tarron Lamont, Marjolaine Krug
Summary: This study compared several satellite-derived sea surface temperature products for research and monitoring applications in the southern African marine region. Overall, there was good agreement between merged sea surface temperature products for most of the region, but strong disagreement was observed at areas with complex temperature structures and strong sea surface temperature gradients. Seasonal bias in temperature discrepancy was found to be influenced by cloud cover and local oceanographic dynamics. Additional methods such as ingesting more in situ observations or daytime satellite acquisitions may be required to improve the representations in merged sea surface temperature products, especially in regions of high temperature variance.
Article
Oceanography
O. J. Houndegnonto, N. Kolodziejczyk, C. Maes, B. Bourles, C. Y. Da-Allada, N. Reul
Summary: In the eastern Gulf of Guinea, freshwater plumes are influenced by rivers, with winter mainly driven by high precipitation rate and Niger River runoff, while summer is mainly driven by horizontal advection; freshwater plumes in different regions exhibit different dynamics, with the northeastern influenced by precipitation and river discharge, and the southeastern mainly influenced by Congo River runoff.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2021)
Article
Meteorology & Atmospheric Sciences
Asmat Ullah, Benjamin Pohl, Julien Pergaud, Bastien Dieppois, Mathieu Rouault
Summary: Rainfall extremes are crucial in semi-arid countries, with large-scale extremes having a significant impact on total rainfall in austral summer. Observations show that large-scale extremes are spatially coherent, while small-scale events are found sporadic in nature.
INTERNATIONAL JOURNAL OF CLIMATOLOGY
(2022)
Article
Meteorology & Atmospheric Sciences
Arielle Stela N. Imbol Nkwinkwa, Mathieu Rouault, Noel Keenlyside, Shunya Koseki
Summary: The study utilized simulations to demonstrate the seasonal impact of the warm core of the Agulhas Current on precipitation in southern Africa. It was found that reducing the temperature of the current led to a decrease in precipitation during the wettest seasons, with a mechanism related to pressure adjustment.
JOURNAL OF CLIMATE
(2021)
Article
Oceanography
Juliano D. Ramanantsoa, P. Penven, R. P. Raj, L. Renault, L. Ponsoni, M. Ostrowski, A. F. Dilmahamod, M. Rouault
Summary: The southern extension of the East Madagascar Current (EMC) can be classified into three states: early retroflection, canonical retroflection, and no retroflection. Understanding the influence of current strength and eddies on retroflection formation can help predict marine phenomena in the southern part of Madagascar.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2021)
Article
Geosciences, Multidisciplinary
James N. Moum, Kenneth G. Hughes, Emily L. Shroyer, William D. Smyth, Deepak Cherian, Sally J. Warner, Bernard Bourles, Peter Brandt, Marcus Dengler
Summary: Multiyear turbulence measurements from oceanographic moorings in equatorial Atlantic and Pacific cold tongues reveal similarities in deep cycle turbulence beneath the mixed layer and above the Equatorial Undercurrent core. Despite differences in surface forcing, EUC strength and core depth DCT occurs, and is consistent in amplitude and timing, at all three sites. A proposed scaling in depth that isolates the deep cycle layers and of epsilon by the product of wind stress and current shear collapses vertical profiles at all sites to within a factor of 2.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Oceanography
M. Rouault, F. S. Tomety
Summary: The study demonstrates the impact of ENSO on the Benguela Current upwelling sea surface temperature, revealing a significant weak correlation between the two particularly in the southern Benguela region with up to 8 months lag.
JOURNAL OF PHYSICAL OCEANOGRAPHY
(2022)
Article
Oceanography
F. M. Awo, M. Rouault, M. Ostrowski, F. S. Tomety, C. Y. Da-Allada, J. Jouanno
Summary: The seasonal cycle of sea surface salinity (SSS) along the Angolan coast was investigated, and the model was able to reproduce the main characteristics of the seasonal cycle. The study found that the meridional advection of surface water, the vertical advection of subsurface water, and mixing at the base of the mixed layer control the semi-annual cycle of SSS.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2022)
Article
Geosciences, Multidisciplinary
Gilles Reverdin, Claire Waelbroeck, Catherine Pierre, Camille Akhoudas, Giovanni Aloisi, Marion Benetti, Bernard Bourles, Magnus Danielsen, Jerome Demange, Denis Diverres, Jean-Claude Gascard, Marie-Noelle Houssais, Herve Le Goff, Pascale Lherminier, Claire Lo Monaco, Herle Mercier, Nicolas Metzl, Simon Morisset, Aicha Naamar, Thierry Reynaud, Jean-Baptiste Sallee, Virginie Thierry, Susan E. Hartman, Edward W. Mawji, Solveig Olafsdottir, Torsten Kanzow, Anton Velo, Antje Voelker, Igor Yashayaev, F. Alexander Haumann, Melanie J. Leng, Carol Arrowsmith, Michael Meredith
Summary: The characteristics and uncertainties of the CISE-LOCEAN seawater isotope dataset (delta O-18, delta H-2, referred to as delta D) are presented in this article. The dataset covers a wide timespan from 1998 to 2021 and includes a large number of data entries. The analysis methods and sources of uncertainties are discussed, including instrumental uncertainty and the isotopic composition of in-house standards. The importance of sample conservation and the need for caution when merging datasets from different laboratories are also highlighted.
EARTH SYSTEM SCIENCE DATA
(2022)
