Projected changes to South Atlantic boundary currents and confluence region in the CMIP5 models: the role of wind and deep ocean changes

The South Atlantic (SA) circulation plays an important role in the oceanic teleconnections from the Indian, Pacific and Southern oceans to the North Atlantic, with inter-hemispheric exchanges of heat and salt. Here, we show that the large-scale features of the SA circulation are projected to change...

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Main Authors: G M Pontes, A Sen Gupta, A S Taschetto
Format: Article
Language:English
Published: IOP Publishing 2016-01-01
Series:Environmental Research Letters
Subjects:
Online Access:https://doi.org/10.1088/1748-9326/11/9/094013
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author G M Pontes
A Sen Gupta
A S Taschetto
author_facet G M Pontes
A Sen Gupta
A S Taschetto
author_sort G M Pontes
collection DOAJ
description The South Atlantic (SA) circulation plays an important role in the oceanic teleconnections from the Indian, Pacific and Southern oceans to the North Atlantic, with inter-hemispheric exchanges of heat and salt. Here, we show that the large-scale features of the SA circulation are projected to change significantly under ‘business as usual’ greenhouse gas increases. Based on 19 models from the Coupled Model Intercomparison Project phase 5  there is a projected weakening in the upper ocean interior transport (<1000 m) between 15° and ∼32°S, largely related to a weakening of the wind stress curl over this region. The reduction in ocean interior circulation is largely compensated by a decrease in the net deep southward ocean transport (>1000 m), mainly related to a decrease in the North Atlantic deep water transport. Between 30° and 40°S, there is a consistent projected intensification in the Brazil current strength of about 40% (30%–58% interquartile range) primarily compensated by an intensification of the upper interior circulation across the Indo-Atlantic basin. The Brazil–Malvinas confluence is projected to shift southwards, driven by a weakening of the Malvinas current. Such a change could have important implications for the distribution of marine species in the southwestern SA in the future.
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spelling doaj.art-624a7fcec6954b70846688a4b9bf37df2023-08-09T14:19:38ZengIOP PublishingEnvironmental Research Letters1748-93262016-01-0111909401310.1088/1748-9326/11/9/094013Projected changes to South Atlantic boundary currents and confluence region in the CMIP5 models: the role of wind and deep ocean changesG M Pontes0https://orcid.org/0000-0003-4397-4238A Sen Gupta1A S Taschetto2School of Oceanography, State University of Rio de Janeiro (UERJ) , Rio de Janeiro, BrazilClimate Change Research Centre and Australian Research Council (ARC) Centre of Excellence for Climate System Science, The University of New South Wales , AustraliaClimate Change Research Centre and Australian Research Council (ARC) Centre of Excellence for Climate System Science, The University of New South Wales , AustraliaThe South Atlantic (SA) circulation plays an important role in the oceanic teleconnections from the Indian, Pacific and Southern oceans to the North Atlantic, with inter-hemispheric exchanges of heat and salt. Here, we show that the large-scale features of the SA circulation are projected to change significantly under ‘business as usual’ greenhouse gas increases. Based on 19 models from the Coupled Model Intercomparison Project phase 5  there is a projected weakening in the upper ocean interior transport (<1000 m) between 15° and ∼32°S, largely related to a weakening of the wind stress curl over this region. The reduction in ocean interior circulation is largely compensated by a decrease in the net deep southward ocean transport (>1000 m), mainly related to a decrease in the North Atlantic deep water transport. Between 30° and 40°S, there is a consistent projected intensification in the Brazil current strength of about 40% (30%–58% interquartile range) primarily compensated by an intensification of the upper interior circulation across the Indo-Atlantic basin. The Brazil–Malvinas confluence is projected to shift southwards, driven by a weakening of the Malvinas current. Such a change could have important implications for the distribution of marine species in the southwestern SA in the future.https://doi.org/10.1088/1748-9326/11/9/094013South Atlantic oceanclimate changeClimate Model Intercomparisson Project-CMIPSverdrup’s dynamicsBrazil currentBrazil–Malvinas confluence
spellingShingle G M Pontes
A Sen Gupta
A S Taschetto
Projected changes to South Atlantic boundary currents and confluence region in the CMIP5 models: the role of wind and deep ocean changes
Environmental Research Letters
South Atlantic ocean
climate change
Climate Model Intercomparisson Project-CMIP
Sverdrup’s dynamics
Brazil current
Brazil–Malvinas confluence
title Projected changes to South Atlantic boundary currents and confluence region in the CMIP5 models: the role of wind and deep ocean changes
title_full Projected changes to South Atlantic boundary currents and confluence region in the CMIP5 models: the role of wind and deep ocean changes
title_fullStr Projected changes to South Atlantic boundary currents and confluence region in the CMIP5 models: the role of wind and deep ocean changes
title_full_unstemmed Projected changes to South Atlantic boundary currents and confluence region in the CMIP5 models: the role of wind and deep ocean changes
title_short Projected changes to South Atlantic boundary currents and confluence region in the CMIP5 models: the role of wind and deep ocean changes
title_sort projected changes to south atlantic boundary currents and confluence region in the cmip5 models the role of wind and deep ocean changes
topic South Atlantic ocean
climate change
Climate Model Intercomparisson Project-CMIP
Sverdrup’s dynamics
Brazil current
Brazil–Malvinas confluence
url https://doi.org/10.1088/1748-9326/11/9/094013
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AT astaschetto projectedchangestosouthatlanticboundarycurrentsandconfluenceregioninthecmip5modelstheroleofwindanddeepoceanchanges