Data/hora: 05/06/2024 17:41:18

Provedor de dados: 	5	
País: 	France	
Título: 	Influence of Tropical Instability Waves on Phytoplankton Biomass near the Marquesas Islands	
Autores: 	Martinez, Elodie; Raapoto, Hirohiti; Maes, Christophe; Maamaatuaihutapu, Keitapu.	
Data: 	2018-04	
Ano: 	2018	
Palavras-chave: 	Tropical instability waves; La Nina; Chlorophyll-a concentration variability; Ocean colour; Island mass effect; Marquesas islands; Oceanography; Satellite observations.	
Resumo: 	The Marquesas form an isolated group of small islands in the Central South Pacific where quasi-permanent biological activity is observed. During La Niña events, this biological activity, shown by a net increase of chlorophyll-a concentration (Chl, a proxy of phytoplankton biomass), is particularly strong. It has been hypothesized that this strong activity is due to iron-rich waters advected from the equatorial region to the Marquesas by tropical instability waves (TIWs). Here we investigate this hypothesis over 18 years by combining satellite observations, re-analyses of ocean data, and Lagrangian diagnostics. Four La Niña events ranging from moderate to strong intensity occurred during this period, and our results show that the Chl plume within the archipelago can be indeed influenced by such equatorial advection, but this was observed during the strong 1998 and 2010 La Niña conditions only. Chl spatio-temporal patterns during the occurrence of other TIWs rather suggest the interaction of large-scale forcing events such as an uplift of the thermocline or the enhancement of coastal upwelling induced by the tropical strengthening of the trades with the islands leading to enhancement of phytoplankton biomass within the surface waters. Overall, whatever the conditions, our analyses suggest that the influence of the TIWs is to disperse, stir, and, therefore, modulate the shape of the existing phytoplankton plume	
Tipo: 	Text	
Idioma: 	Inglês	
Identificador: 	https://archimer.ifremer.fr/doc/00437/54858/56346.pdf

DOI:10.3390/rs10040640

https://archimer.ifremer.fr/doc/00437/54858/	
Editor: 	Mdpi	
Formato: 	application/pdf	
Fonte: 	Remote Sensing (2072-4292) (Mdpi), 2018-04 , Vol. 10 , N. 4 , P. 640 (12p.)	
Fonte: 	2018 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).

info:eu-repo/semantics/openAccess

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