FN Archimer Export Format
PT J
TI Influence of the phytoplankton community composition on the in situ fluorescence signal: Implication for an improved estimation of the chlorophyll-a concentration from BioGeoChemical-Argo profiling floats
BT 
AF Petit, Flavien
   Uitz, Julia
   Schmechtig, Catherine
   Dimier, Céline
   Ras, Joséphine
   Poteau, Antoine
   Golbol, Melek
   Vellucci, Vincenzo
   Claustre, Hervé
AS 1:1;2:1;3:2;4:3;5:1;6:1;7:3;8:3;9:1;
FF 1:;2:;3:;4:;5:;6:;7:;8:;9:;
C1 Centre national de la Recherche Scientifique (CNRS) and Sorbonne Universite´ , Laboratoire d’Oce´ anographie de Villefranche (LOV), Villefranche-sur-Mer, France
   Centre national de la Recherche Scientifique (CNRS) and Sorbonne Université, Observatoire des Sciences de l’Univers (OSU) Ecce Terra, Paris, France
   Observatoire des Sciences de l’Univers (OSU) and Sorbonne Université, Institut de la Mer de Villefranche (IMEV), Villefranche-sur-Mer, France
C2 CNRS, FRANCE
   CNRS, FRANCE
   UNIV SORBONNE, FRANCE
IN DOAJ
IF 3.7
TC 5
UR https://archimer.ifremer.fr/doc/00796/90786/96405.pdf
   https://archimer.ifremer.fr/doc/00796/90786/96406.docx
LA English
DT Article
CR BIO-ARGO-MED-2015
   BIO-ARGO-MED-2018
   BOUSSOLE
   MD 205 / SOCLIM
   MOBYDICK-THEMISTO
   OISO - OCÉAN INDIEN SERVICE D'OBSERVATION
BO Téthys II
   Marion Dufresne
DE ;Phytoplankton biomass;in-situ fluorescence;BGC-Argo floats;phytoplankton community composition;chlorophyll-a concentration;phytoplankton absorption
AB In-situ fluorescence is a widely used method to estimate the chlorophyll-a (Chla) concentration, a proxy of the phytoplankton biomass. With the emergence of autonomous platforms such as BioGeoChemical-Argo (BGC-Argo) profiling floats, its use has expanded to global scale observations. However, the relationship between in-situ fluorescence and Chla may vary significantly, leading to major discrepancies between oceanic regions. This study aims to investigate the main sources of the natural variability in the in-situ fluorescence signal in the global open ocean, specifically the influence of the phytoplankton community composition. In this view, we analyzed a combination of three datasets comprising concomitant measurements of in-situ fluorescence, pigment concentrations and phytoplankton absorption spectra. Two datasets cover several contrasted bioregions of the global ocean whereas the third one consists of a regional time series in the northwestern Mediterranean Sea, which allows to examine the effect of phytoplankton community composition on the fluorescence signal on the global, seasonal and vertical scales. We studied the variability of the two major drivers of the natural variability of the fluorescence process, i.e. the light absorption and the fluorescence quantum yield of phytoplankton, in regards of the variability of the pigment composition of the communities. The community composition correlates substantially with the Chla-to-fluorescence ratio, with high fluorescence values associated with phytoplankton communities dominated by large cells. This trend may be explained by the combined effects of the community composition on the phytoplankton absorption coefficient and the fluorescence quantum yield, and is consistently observed globally, seasonally and vertically. Non-photosynthetic pigments also appear to play a critical role in oligotrophic surface waters, leading to a reduction of the quantum yield of fluorescence. The results indicate that the phytoplankton community composition plays a key role in the relationship between the in-situ fluorescence signal and Chla concentration. Therefore, we suggest that taking into account the composition of phytoplankton communities in the retrieval of the Chla concentration from current in-situ fluorometers, those mounted on BGC-Argo floats in particular, would lead to a better estimation of the phytoplankton biomass on a wide range of spatial and temporal scales. 
PY 2022
PD SEP
SO Frontiers In Marine Science
SN 2296-7745
PU Frontiers Media SA
VL 9
UT 000876368900001
DI 10.3389/fmars.2022.959131
ID 90786
ER

EF