A comparative study of biological production in eastern boundary upwelling systems using an artificial neural network

Eastern Boundary Upwelling Systems (EBUS) are highly productive ocean regions. Yet, substantial differences in net primary production (NPP) exist within and between these systems for reasons that are still not fully understood. Here, we explore the leading physical processes and environmental factor...

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Main Authors: Z. Lachkar, N. Gruber
Format: Article
Language:English
Published: Copernicus Publications 2012-01-01
Series:Biogeosciences
Online Access:http://www.biogeosciences.net/9/293/2012/bg-9-293-2012.pdf
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author Z. Lachkar
N. Gruber
author_facet Z. Lachkar
N. Gruber
author_sort Z. Lachkar
collection DOAJ
description Eastern Boundary Upwelling Systems (EBUS) are highly productive ocean regions. Yet, substantial differences in net primary production (NPP) exist within and between these systems for reasons that are still not fully understood. Here, we explore the leading physical processes and environmental factors controlling NPP in EBUS through a comparative study of the California, Canary, Benguela, and Humboldt Current systems. The NPP drivers are identified with the aid of an artificial neural network analysis based on self-organizing-maps (SOM). Our results suggest that in addition to the expected NPP enhancing effect of stronger equatorward alongshore wind, three factors have an inhibiting effect: (1) strong eddy activity, (2) narrow continental shelf, and (3) deep mixed layer. The co-variability of these 4 drivers defines in the context of the SOM a continuum of 100 patterns of NPP regimes in EBUS. These are grouped into 4 distinct classes using a Hierarchical Agglomerative Clustering (HAC) method. Our objective classification of EBUS reveals important variations of NPP regimes within each of the four EBUS, particularly in the Canary and Benguela Current systems. Our results show that the Atlantic EBUS are generally more productive and more sensitive to upwelling favorable winds because of weaker factors inhibiting NPP. Perturbations of alongshore winds associated with climate change may therefore lead to contrasting biological responses in the Atlantic and the Pacific EBUS.
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spelling doaj.art-f045aa1913c64afa9768818e878c3b0c2022-12-22T01:09:27ZengCopernicus PublicationsBiogeosciences1726-41701726-41892012-01-019129330810.5194/bg-9-293-2012A comparative study of biological production in eastern boundary upwelling systems using an artificial neural networkZ. Lachkar0N. Gruber1Environmental Physics, Institute of Biogeochemistry and Pollutant Dynamics, ETH Zurich, Universitätstrasse 16, 8092 Zurich, SwitzerlandEnvironmental Physics, Institute of Biogeochemistry and Pollutant Dynamics, ETH Zurich, Universitätstrasse 16, 8092 Zurich, SwitzerlandEastern Boundary Upwelling Systems (EBUS) are highly productive ocean regions. Yet, substantial differences in net primary production (NPP) exist within and between these systems for reasons that are still not fully understood. Here, we explore the leading physical processes and environmental factors controlling NPP in EBUS through a comparative study of the California, Canary, Benguela, and Humboldt Current systems. The NPP drivers are identified with the aid of an artificial neural network analysis based on self-organizing-maps (SOM). Our results suggest that in addition to the expected NPP enhancing effect of stronger equatorward alongshore wind, three factors have an inhibiting effect: (1) strong eddy activity, (2) narrow continental shelf, and (3) deep mixed layer. The co-variability of these 4 drivers defines in the context of the SOM a continuum of 100 patterns of NPP regimes in EBUS. These are grouped into 4 distinct classes using a Hierarchical Agglomerative Clustering (HAC) method. Our objective classification of EBUS reveals important variations of NPP regimes within each of the four EBUS, particularly in the Canary and Benguela Current systems. Our results show that the Atlantic EBUS are generally more productive and more sensitive to upwelling favorable winds because of weaker factors inhibiting NPP. Perturbations of alongshore winds associated with climate change may therefore lead to contrasting biological responses in the Atlantic and the Pacific EBUS.http://www.biogeosciences.net/9/293/2012/bg-9-293-2012.pdf
spellingShingle Z. Lachkar
N. Gruber
A comparative study of biological production in eastern boundary upwelling systems using an artificial neural network
Biogeosciences
title A comparative study of biological production in eastern boundary upwelling systems using an artificial neural network
title_full A comparative study of biological production in eastern boundary upwelling systems using an artificial neural network
title_fullStr A comparative study of biological production in eastern boundary upwelling systems using an artificial neural network
title_full_unstemmed A comparative study of biological production in eastern boundary upwelling systems using an artificial neural network
title_short A comparative study of biological production in eastern boundary upwelling systems using an artificial neural network
title_sort comparative study of biological production in eastern boundary upwelling systems using an artificial neural network
url http://www.biogeosciences.net/9/293/2012/bg-9-293-2012.pdf
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