Sea surface kinetic energy as a proxy for mesoscale light limitation for phyoplankton in the Southern Ocean
The Southern Ocean is classified as a high nutrient, low chlorophyll region as surface waters are typically macro-nutrient (e.g. nitrogen and phosphorous) rich in the austral summer, yet they are characterized by patchy, intense phytoplankton blooms within a generally unproductive environment. The m...
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ftunivdelaware:oai:udspace.udel.edu:19716/24139 2023-06-11T04:16:53+02:00 Sea surface kinetic energy as a proxy for mesoscale light limitation for phyoplankton in the Southern Ocean Gradone, Joseph Christopher 2019-02-15T17:02:16Z application/pdf http://udspace.udel.edu/handle/19716/24139 en eng University of Delaware https://search.proquest.com/docview/2194307524?accountid=10457 1100471111 http://udspace.udel.edu/handle/19716/24139 Thesis 2019 ftunivdelaware 2023-05-01T12:58:12Z The Southern Ocean is classified as a high nutrient, low chlorophyll region as surface waters are typically macro-nutrient (e.g. nitrogen and phosphorous) rich in the austral summer, yet they are characterized by patchy, intense phytoplankton blooms within a generally unproductive environment. The mechanisms controlling phytoplankton abundance include turbulent mixing, available light, respiration and predation rates, and nutrient availability. While there is much debate about the initiation of phytoplankton blooms in the Southern Ocean, there is also significant variation in phytoplankton bloom dynamics within a growing season, suggesting many different mechanisms are contributing to patchy phytoplankton distributions. ☐ Using data from 2003 to 2017, a surprising relationship between in situ and satellite-derived chlorophyll and modelled kinetic energy was observed. High chlorophyll concentrations were not observed in either remotely sensed or in situ data while kinetic energy was high throughout the entire Southern Ocean. Consequently, low kinetic energy appears to be a necessary, but not sufficient, precondition for phytoplankton blooms throughout the Southern Ocean. In December, surface phytoplankton concentration appears to decrease due to high kinetic energy simply diluting their concentration in the water column. However, in January and February high kinetic energy appears to limit phytoplankton abundance through a mesoscale light limitation by decreasing the time they spend in the euphotic zone. Analysis of this relationship through a time dependent, probabilistic model, combined with in-situ observations of water column structure show that high kinetic energy deepens the mixed layer through turbulent mixing, potentially limiting the availability of light. These probabilistic models suggest that the spatial pattern in kinetic energy in the Southern Ocean explains up to 30% of the variability in the distribution of chlorophyll concentration. These findings indicate that KE is a significant factor in ... Thesis Southern Ocean The University of Delaware Library Institutional Repository Southern Ocean Austral |
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Open Polar |
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The University of Delaware Library Institutional Repository |
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ftunivdelaware |
language |
English |
description |
The Southern Ocean is classified as a high nutrient, low chlorophyll region as surface waters are typically macro-nutrient (e.g. nitrogen and phosphorous) rich in the austral summer, yet they are characterized by patchy, intense phytoplankton blooms within a generally unproductive environment. The mechanisms controlling phytoplankton abundance include turbulent mixing, available light, respiration and predation rates, and nutrient availability. While there is much debate about the initiation of phytoplankton blooms in the Southern Ocean, there is also significant variation in phytoplankton bloom dynamics within a growing season, suggesting many different mechanisms are contributing to patchy phytoplankton distributions. ☐ Using data from 2003 to 2017, a surprising relationship between in situ and satellite-derived chlorophyll and modelled kinetic energy was observed. High chlorophyll concentrations were not observed in either remotely sensed or in situ data while kinetic energy was high throughout the entire Southern Ocean. Consequently, low kinetic energy appears to be a necessary, but not sufficient, precondition for phytoplankton blooms throughout the Southern Ocean. In December, surface phytoplankton concentration appears to decrease due to high kinetic energy simply diluting their concentration in the water column. However, in January and February high kinetic energy appears to limit phytoplankton abundance through a mesoscale light limitation by decreasing the time they spend in the euphotic zone. Analysis of this relationship through a time dependent, probabilistic model, combined with in-situ observations of water column structure show that high kinetic energy deepens the mixed layer through turbulent mixing, potentially limiting the availability of light. These probabilistic models suggest that the spatial pattern in kinetic energy in the Southern Ocean explains up to 30% of the variability in the distribution of chlorophyll concentration. These findings indicate that KE is a significant factor in ... |
format |
Thesis |
author |
Gradone, Joseph Christopher |
spellingShingle |
Gradone, Joseph Christopher Sea surface kinetic energy as a proxy for mesoscale light limitation for phyoplankton in the Southern Ocean |
author_facet |
Gradone, Joseph Christopher |
author_sort |
Gradone, Joseph Christopher |
title |
Sea surface kinetic energy as a proxy for mesoscale light limitation for phyoplankton in the Southern Ocean |
title_short |
Sea surface kinetic energy as a proxy for mesoscale light limitation for phyoplankton in the Southern Ocean |
title_full |
Sea surface kinetic energy as a proxy for mesoscale light limitation for phyoplankton in the Southern Ocean |
title_fullStr |
Sea surface kinetic energy as a proxy for mesoscale light limitation for phyoplankton in the Southern Ocean |
title_full_unstemmed |
Sea surface kinetic energy as a proxy for mesoscale light limitation for phyoplankton in the Southern Ocean |
title_sort |
sea surface kinetic energy as a proxy for mesoscale light limitation for phyoplankton in the southern ocean |
publisher |
University of Delaware |
publishDate |
2019 |
url |
http://udspace.udel.edu/handle/19716/24139 |
geographic |
Southern Ocean Austral |
geographic_facet |
Southern Ocean Austral |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_relation |
https://search.proquest.com/docview/2194307524?accountid=10457 1100471111 http://udspace.udel.edu/handle/19716/24139 |
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1768375551379111936 |