scholarly journals Marine climate change over the eastern Agulhas Bank of South Africa

Ocean Science ◽  
2020 ◽  
Vol 16 (6) ◽  
pp. 1529-1544
Author(s):  
Mark R. Jury
Keyword(s):  
Climate Change ◽  
South Africa ◽  
Large Scale ◽  
Time Span ◽  
Rate Of Change ◽  
Sea Surface ◽  
Ensemble Model ◽  
Agulhas Current ◽  
Marine Climate ◽  
Subtropical Ridge

Abstract. The rate of change in the marine environment over the eastern Agulhas Bank along the south coast of South Africa (32–37∘ S, 20–30∘ E) is studied using reanalysis observations for 1900–2015 and coupled ensemble model projections for 1980–2100. Outcomes are influenced by resolution and time span: ∼ 1∘ datasets covering the whole period capture large-scale changes, while ∼ 0.5∘ datasets in the satellite era better distinguish the cross-shelf gradients. Although sea surface temperatures offshore are warming rapidly (0.05 ∘C yr−1 since 1980), a trend toward easterly winds and a locally stronger Agulhas Current have intensified nearshore upwelling (−0.03 ∘C yr−1). The subtropical ridge is gradually moving poleward, leading to a drier climate.

scholarly journals Marine climate change over the eastern Agulhas Bank of South Africa

2020 ◽  
Author(s):  
Mark R. Jury
Keyword(s):  
South Africa ◽  
Large Scale ◽  
Southern Oscillation ◽  
Rate Of Change ◽  
Sea Surface ◽  
Ensemble Model ◽  
Agulhas Current ◽  
Near Shore ◽  
Marine Climate ◽  
High Phase

Abstract. The rate of change in the marine environment along the south coast of South Africa (32–37 S, 20–30 E) is studied using reanalysis observations 1900–2015 and coupled ensemble model projections 1980–2100. Outcomes are influenced by resolution and time-span: ~1 degree datasets covering the whole period capture large-scale changes, while ~0.5 degree datasets in the satellite era better distinguish the cross-shelf gradients. Although sea surface temperatures off-shore are warming rapidly (.05 °C/yr since 1980), a trend toward easterly winds and a stronger Agulhas Current have intensified near-shore upwelling (-.03 °C/yr). The sub-tropical ridge during summer is drawn poleward by global warming and high phase southern oscillation index. Cooler inshore sea temperatures suppress latent heat flux and contribute to coastal desiccation (-.005 mm day−1/yr) and vegetation warming (.1 °C/yr) since 1980. Coupled ensemble projections from the Hadley and European models indicate that the shift toward drier weather and easterly winds may be sustained through the 21st century.

Impact of Climate Change on the Agulhas Bank, South Africa ― a 100 year projection with consequences for the squid fishery

2020 ◽  
Author(s):  
Sarah Asdar ◽  
Michael J. Roberts ◽  
Zoe Jacobs ◽  
Ekaterina Popova
Keyword(s):  
Climate Change ◽  
South Africa ◽  
Water Retention ◽  
East Coast ◽  
Surface Current ◽  
Economic Importance ◽  
Economic Consequences ◽  
Local Circulation ◽  
Agulhas Current ◽  
Ocean Biogeochemistry

<p>The South and East coast of South Africa is strongly influenced by the warm, fast-flowing Agulhas Current. The Agulhas Bank, a shallow shelf on the southern tip of Southern Africa, is a crucial area for productivity which support fisheries of high economic importance for South Africa.  In this context of climate change, perturbations of this diverse, complex and highly variable marine environment could affect the productivity and lead to dramatic social and economic consequences for the region. To predict potential changes over the eastern and central Bank, we employ a high-resolution global coupled ocean-biogeochemistry model, NEMO-MEDUSA, simulated to year 2099. We find that even though the Agulhas Bank is warming over the next century, primary production does not experience a significant decrease. Additionally, we show that the Agulhas Current might shift its position, with intensification surface current velocity on the Bank hence reducing water retention over the Bank. This change in local circulation over the Bank could have a serious impact on the ecosystem of the region.</p>

scholarly journals Effects of Large-Scale Oceanic Phenomena on Non-Cholera Vibriosis Incidence in the United States: Implications for Climate Change

2019 ◽  
Author(s):  
Chloë Logar-Henderson ◽  
Rebecca Ling ◽  
Ashleigh R. Tuite ◽  
David N. Fisman
Keyword(s):  
Public Health ◽  
Climate Change ◽  
United States ◽  
Large Scale ◽  
Disease Incidence ◽  
The United States ◽  
Ocean Warming ◽  
Rate Of Change ◽  
Health Concern ◽  
Increased Risk

AbstractPurposeEpidemics of diarrhea caused by toxigenic strains of Vibrio cholerae are of global public health concern, but non-cholera Vibrio (NCV) species are also important causes of disease. These pathogens are thermophilic, and climate change could increase the risk of NCV infection. The El Niño Southern Oscillation (ENSO) is a “natural experiment” that may presage ocean warming effects on disease incidence.MethodWe obtained vibriosis case counts in the United States by digitizing annual reports from the U.S. Cholera and Other Vibrio Illness Surveillance system. Trends and environmental impacts (of ENSO and the North Atlantic Oscillation) were evaluated using negative binomial and distributed nonlinear lag models. Associations between latitude and changing risk were evaluated with meta-regression.ResultsTrend models demonstrated significant seasonality (P < 0.001) and a 7% annual increase in disease risk from 1999 to 2014 (annual IRR 1.071, 95% CI 1.061-1.081). Distributed lag models demonstrated increased vibriosis risk following ENSO conditions over the subsequent 12 months (integrated RR 1.940, 95% CI 1.298-2.901). The rate of change in vibriosis risk increased with state latitude (RR per 10° increase 1.066, 95% CI 1.027-1.107).ConclusionVibriosis risk in the United States appears to be impacted by irregular large-scale ocean warming and exhibits a north-south gradient in rate of change as would be expected if changing disease incidence is attributable to ocean warming. Vulnerable populations, which include high-income countries with well-developed public health systems, may experience increased risk of this disease as a result of climate change.

Impacts of SST Anomalies in the Agulhas Current System on the Regional Climate Variability

2012 ◽  
Vol 25 (4) ◽  
pp. 1213-1229 ◽  
Author(s):  
Mototaka Nakamura
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Large Scale ◽  
Current System ◽  
Regional Climate ◽  
Sea Surface ◽  
Near Surface ◽  
Agulhas Current ◽  
Sea Surface Temperature Anomalies ◽  
Potential Impact

Abstract The potential impact of the variability in the Agulhas Current system on the large-scale atmospheric state in the Southern Hemisphere is examined, using the monthly near-surface baroclinicity as the key parameter, for the period between September 1980 and August 2002. Dominant patterns of anomalous near-surface baroclinicity found from empirical orthogonal function (EOF) analyses in the region that includes most of the Agulhas Current system show a wide variety of anomaly patterns: some of which indicate spatial shifts in the position of the Agulhas Retroflection and/or Agulhas Return Current. Composited anomalies in various atmospheric fields, sea surface temperature, and the net surface heat flux at the air–sea boundary based on the signals in the EOFs suggest that sea surface temperature anomalies in the Agulhas Current system thermally force the atmosphere on the synoptic scale via modification of the near-surface baroclinicity in March and April and possibly in January and February as well.

The World Economic Forum Principles on "Climate Governance on Corporate Boards": can soft law help to face climate change around the world?

2020 ◽  
pp. 37-55
Author(s):  
Sabrina Bruno
Keyword(s):  
Climate Change ◽  
South Africa ◽  
Comparative Analysis ◽  
Boards Of Directors ◽  
Soft Law ◽  
Corporate Boards ◽  
World Economic Forum ◽  
Financial Factor ◽  
The World ◽  
World Economic

Climate change is a financial factor that carries with it risks and opportunities for companies. To support boards of directors of companies belonging to all jurisdictions, the World Economic Forum issued in January 2019 eight Principlescontaining both theoretical and practical provisions on: climate accountability, competence, governance, management, disclosure and dialogue. The paper analyses each Principle to understand scope and managerial consequences for boards and to evaluate whether the legal distinctions, among the various jurisdictions, may undermine the application of the Principles or, by contrast, despite the differences the Principles may be a useful and effective guidance to drive boards' of directors' conduct around the world in handling climate change challenges. Five jurisdictions are taken into consideration for this comparative analysis: Europe (and UK), US, Australia, South Africa and Canada. The conclusion is that the WEF Principles, as soft law, is the best possible instrument to address boards of directors of worldwide companies, harmonise their conduct and effectively help facing such global emergency.

DESIGN AND IMPLEMENTATION OF THE OCEANOGRAPHIC MODELING AND OBSERVATION NETWORK (REMO) FOR PHYSICAL OCEANOGRAPHY STUDIES AND OCEAN FORECASTING

2014 ◽  
Vol 31 (2) ◽  
Author(s):  
Jose Antonio Moreira Lima
Keyword(s):  
Atlantic Ocean ◽  
Large Scale ◽  
North Pacific Ocean ◽  
Integrated Approach ◽  
Sea Surface ◽  
Global Ocean ◽  
Height Anomaly ◽  
The North ◽  
Observation Network ◽  
Ocean Forecasting

This paper is concerned with the planning, implementation and some results of the Oceanographic Modeling and Observation Network, named REMO, for Brazilian regional waters. Ocean forecasting has been an important scientific issue over the last decade due to studies related to climate change as well as applications related to short-range oceanic forecasts. The South Atlantic Ocean has a deficit of oceanographic measurements when compared to other ocean basins such as the North Atlantic Ocean and the North Pacific Ocean. It is a challenge to design an ocean forecasting system for a region with poor observational coverage of in-situ data. Fortunately, most ocean forecasting systems heavily rely on the assimilation of surface fields such as sea surface height anomaly (SSHA) or sea surface temperature (SST), acquired by environmental satellites, that can accurately provide information that constrain major surface current systems and their mesoscale activity. An integrated approach is proposed here in which the large scale circulation in the Atlantic Ocean is modeled in a first step, and gradually nested into higher resolution regional models that are able to resolve important processes such as the Brazil Current and associated mesoscale variability, continental shelf waves, local and remote wind forcing, and others. This article presents the overall strategy to develop the models using a network of Brazilian institutions and their related expertise along with international collaboration. This work has some similarity with goals of the international project Global Ocean Data Assimilation Experiment OceanView (GODAE OceanView).

BIOGENIC OPAL PRODUCTION IN THE AGULHAS CURRENT AND ITS CONNECTION TO ARIDIFICATION IN SOUTH AFRICA DURING THE MID-PLEISTOCENE

2018 ◽  
Author(s):  
Eduardo Ruiz Marin ◽  
◽  
Jason Coenen ◽  
Reed P. Scherer ◽  
Nathan D. Stansell ◽  
...  
Keyword(s):  
South Africa ◽  
Agulhas Current ◽  
Biogenic Opal
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