Response of the deep chlorophyll maximum to fluctuations in vertical mixing intensity
Extreme atmospheric events, such as storms, can temporarily increase the vertical diffusivity in the upper ocean by several orders of magnitude, causing variability in the deep chlorophyll maximum (DCM). In this study, we investigate the impact of intermittent vertical mixing on the deep chlorophyll...
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ftunivnapoliiris:oai:www.iris.unina.it:11588/568409 2024-09-09T19:58:32+00:00 Response of the deep chlorophyll maximum to fluctuations in vertical mixing intensity LICCARDO, ANTONELLA Annalisa Fierro Daniele Iudicone Pascale Bouruet Aubertot Laurent Dubroca Liccardo, Antonella Annalisa, Fierro Daniele, Iudicone Pascale Bouruet, Aubertot Laurent, Dubroca 2013 http://hdl.handle.net/11588/568409 https://doi.org/10.1016/j.pocean.2012.09.004 http://www.sciencedirect.com/science/article/pii/S0079661112001139 eng eng info:eu-repo/semantics/altIdentifier/wos/WOS:000315059200003 volume:109 firstpage:33 lastpage:46 numberofpages:14 journal:PROGRESS IN OCEANOGRAPHY http://hdl.handle.net/11588/568409 doi:10.1016/j.pocean.2012.09.004 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-84872790473 http://www.sciencedirect.com/science/article/pii/S0079661112001139 info:eu-repo/semantics/article 2013 ftunivnapoliiris https://doi.org/10.1016/j.pocean.2012.09.004 2024-06-17T15:19:30Z Extreme atmospheric events, such as storms, can temporarily increase the vertical diffusivity in the upper ocean by several orders of magnitude, causing variability in the deep chlorophyll maximum (DCM). In this study, we investigate the impact of intermittent vertical mixing on the deep chlorophyll maximum. For this purpose, we analyze a one-dimensional phytoplankton-nutrient model exposed to short-term fluctuations in vertical diffusivity generated by internal waves. As a first step, we use singular perturbations to analyze the impact of a single burst of turbulence on the DCM characteristics. The simulations show that the DCM exhibits a long transient response, even after a single short perturbation. In particular, a single burst of turbulence (i) spreads out the DCM, thereby reducing the local phytoplankton maximum, and (ii) gives rise to a diffusion-driven enhancement of nutrient availability, producing a temporary increase in the phytoplankton growth rates at and above the DCM. Subsequently, we introduce a realistic annual sequence of fluctuations in vertical diffusivity in our model, and we also incorporate the seasonal cycle of light conditions. Fluctuations in vertical diffusivity were derived from high-resolution measurements from the POMME experiment in the north-east Atlantic Ocean, where the contribution of internal waves to the variation in vertical mixing has been characterized for more than one year. The annual light cycle, in combination with intermittent vertical mixing, leads to the superposition of a series of complex dynamical responses. At seasonal and shorter time scales, the vertically integrated productivity is temporally augmented by periods of medium/high diffusivity. Seasonal variation in light availability modifies the DCM response to mixing variability. Article in Journal/Newspaper North East Atlantic IRIS Università degli Studi di Napoli Federico II Progress in Oceanography 109 33 46 |
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IRIS Università degli Studi di Napoli Federico II |
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ftunivnapoliiris |
language |
English |
description |
Extreme atmospheric events, such as storms, can temporarily increase the vertical diffusivity in the upper ocean by several orders of magnitude, causing variability in the deep chlorophyll maximum (DCM). In this study, we investigate the impact of intermittent vertical mixing on the deep chlorophyll maximum. For this purpose, we analyze a one-dimensional phytoplankton-nutrient model exposed to short-term fluctuations in vertical diffusivity generated by internal waves. As a first step, we use singular perturbations to analyze the impact of a single burst of turbulence on the DCM characteristics. The simulations show that the DCM exhibits a long transient response, even after a single short perturbation. In particular, a single burst of turbulence (i) spreads out the DCM, thereby reducing the local phytoplankton maximum, and (ii) gives rise to a diffusion-driven enhancement of nutrient availability, producing a temporary increase in the phytoplankton growth rates at and above the DCM. Subsequently, we introduce a realistic annual sequence of fluctuations in vertical diffusivity in our model, and we also incorporate the seasonal cycle of light conditions. Fluctuations in vertical diffusivity were derived from high-resolution measurements from the POMME experiment in the north-east Atlantic Ocean, where the contribution of internal waves to the variation in vertical mixing has been characterized for more than one year. The annual light cycle, in combination with intermittent vertical mixing, leads to the superposition of a series of complex dynamical responses. At seasonal and shorter time scales, the vertically integrated productivity is temporally augmented by periods of medium/high diffusivity. Seasonal variation in light availability modifies the DCM response to mixing variability. |
author2 |
Liccardo, Antonella Annalisa, Fierro Daniele, Iudicone Pascale Bouruet, Aubertot Laurent, Dubroca |
format |
Article in Journal/Newspaper |
author |
LICCARDO, ANTONELLA Annalisa Fierro Daniele Iudicone Pascale Bouruet Aubertot Laurent Dubroca |
spellingShingle |
LICCARDO, ANTONELLA Annalisa Fierro Daniele Iudicone Pascale Bouruet Aubertot Laurent Dubroca Response of the deep chlorophyll maximum to fluctuations in vertical mixing intensity |
author_facet |
LICCARDO, ANTONELLA Annalisa Fierro Daniele Iudicone Pascale Bouruet Aubertot Laurent Dubroca |
author_sort |
LICCARDO, ANTONELLA |
title |
Response of the deep chlorophyll maximum to fluctuations in vertical mixing intensity |
title_short |
Response of the deep chlorophyll maximum to fluctuations in vertical mixing intensity |
title_full |
Response of the deep chlorophyll maximum to fluctuations in vertical mixing intensity |
title_fullStr |
Response of the deep chlorophyll maximum to fluctuations in vertical mixing intensity |
title_full_unstemmed |
Response of the deep chlorophyll maximum to fluctuations in vertical mixing intensity |
title_sort |
response of the deep chlorophyll maximum to fluctuations in vertical mixing intensity |
publishDate |
2013 |
url |
http://hdl.handle.net/11588/568409 https://doi.org/10.1016/j.pocean.2012.09.004 http://www.sciencedirect.com/science/article/pii/S0079661112001139 |
genre |
North East Atlantic |
genre_facet |
North East Atlantic |
op_relation |
info:eu-repo/semantics/altIdentifier/wos/WOS:000315059200003 volume:109 firstpage:33 lastpage:46 numberofpages:14 journal:PROGRESS IN OCEANOGRAPHY http://hdl.handle.net/11588/568409 doi:10.1016/j.pocean.2012.09.004 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-84872790473 http://www.sciencedirect.com/science/article/pii/S0079661112001139 |
op_doi |
https://doi.org/10.1016/j.pocean.2012.09.004 |
container_title |
Progress in Oceanography |
container_volume |
109 |
container_start_page |
33 |
op_container_end_page |
46 |
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1809929583394291712 |