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Enhanced phytoplankton bloom triggered by atmospheric high-pressure systems over the Northern Arabian Sea

During winter, the dry, cool air brought by prevailing northeasterly trade winds leads to surface ocean heat loss and convective mixing in the northern Arabian Sea. The current paradigm is that the convective mixing process leads to the injection of nutrients up into the surface waters and exert a d...

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Autor principal: Thoppil, Prasad G.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2023
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9840610/
https://www.ncbi.nlm.nih.gov/pubmed/36641538
http://dx.doi.org/10.1038/s41598-023-27785-z
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author Thoppil, Prasad G.
author_facet Thoppil, Prasad G.
author_sort Thoppil, Prasad G.
collection PubMed
description During winter, the dry, cool air brought by prevailing northeasterly trade winds leads to surface ocean heat loss and convective mixing in the northern Arabian Sea. The current paradigm is that the convective mixing process leads to the injection of nutrients up into the surface waters and exert a dominant control on winter productivity. By combining a variety of observations, atmospheric reanalysis and model simulations, we unraveled the processes responsible for the observed year-to-year chlorophyll-a variations in the northern Arabian Sea. Our findings suggest that the atmospheric high-pressure systems that traverse the northern Arabian Sea every winter and spring disrupt winter convective mixing and create an array of environmental conditions conducive to trigger phytoplankton blooms. The arrival of an atmospheric high with the anticyclonic flow in the northern Arabia Sea sets the stage for a sequence of events culminating in intermittent mixed-layer restratification due to buoyancy gain aided by increased specific humidity, supplemented with abundant sunlight due to clear skies, and suppressed turbulent mixing owing to weak winds. These combined with the mixed layer that is shallower than the euphotic zone and the influx of nutrients into the euphotic zone brought by convective mixing between the calm periods, caused unprecedented high concentrations of chlorophyll-a in the northern Arabian Sea.
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spelling pubmed-98406102023-01-16 Enhanced phytoplankton bloom triggered by atmospheric high-pressure systems over the Northern Arabian Sea Thoppil, Prasad G. Sci Rep Article During winter, the dry, cool air brought by prevailing northeasterly trade winds leads to surface ocean heat loss and convective mixing in the northern Arabian Sea. The current paradigm is that the convective mixing process leads to the injection of nutrients up into the surface waters and exert a dominant control on winter productivity. By combining a variety of observations, atmospheric reanalysis and model simulations, we unraveled the processes responsible for the observed year-to-year chlorophyll-a variations in the northern Arabian Sea. Our findings suggest that the atmospheric high-pressure systems that traverse the northern Arabian Sea every winter and spring disrupt winter convective mixing and create an array of environmental conditions conducive to trigger phytoplankton blooms. The arrival of an atmospheric high with the anticyclonic flow in the northern Arabia Sea sets the stage for a sequence of events culminating in intermittent mixed-layer restratification due to buoyancy gain aided by increased specific humidity, supplemented with abundant sunlight due to clear skies, and suppressed turbulent mixing owing to weak winds. These combined with the mixed layer that is shallower than the euphotic zone and the influx of nutrients into the euphotic zone brought by convective mixing between the calm periods, caused unprecedented high concentrations of chlorophyll-a in the northern Arabian Sea. Nature Publishing Group UK 2023-01-14 /pmc/articles/PMC9840610/ /pubmed/36641538 http://dx.doi.org/10.1038/s41598-023-27785-z Text en © This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply 2023 https://creativecommons.org/licenses/by/4.0/Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/ (https://creativecommons.org/licenses/by/4.0/) .
spellingShingle Article
Thoppil, Prasad G.
Enhanced phytoplankton bloom triggered by atmospheric high-pressure systems over the Northern Arabian Sea
title Enhanced phytoplankton bloom triggered by atmospheric high-pressure systems over the Northern Arabian Sea
title_full Enhanced phytoplankton bloom triggered by atmospheric high-pressure systems over the Northern Arabian Sea
title_fullStr Enhanced phytoplankton bloom triggered by atmospheric high-pressure systems over the Northern Arabian Sea
title_full_unstemmed Enhanced phytoplankton bloom triggered by atmospheric high-pressure systems over the Northern Arabian Sea
title_short Enhanced phytoplankton bloom triggered by atmospheric high-pressure systems over the Northern Arabian Sea
title_sort enhanced phytoplankton bloom triggered by atmospheric high-pressure systems over the northern arabian sea
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9840610/
https://www.ncbi.nlm.nih.gov/pubmed/36641538
http://dx.doi.org/10.1038/s41598-023-27785-z
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