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Controls on the distribution of fluorescent dissolved organic matter during an under‐ice algal bloom in the western Arctic Ocean

In this study we used fluorescence excitation and emission matrix spectroscopy, hydrographic data, and a self‐organizing map (SOM) analysis to assess the spatial distribution of labile and refractory fluorescent dissolved organic matter (FDOM) for the Chukchi and Beaufort Seas at the time of a massi...

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Autores principales: Mendoza, Wilson G., Weiss, Elliot L., Schieber, Brian, Greg Mitchell, B.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: John Wiley and Sons Inc. 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5606507/
https://www.ncbi.nlm.nih.gov/pubmed/28989231
http://dx.doi.org/10.1002/2016GB005569
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author Mendoza, Wilson G.
Weiss, Elliot L.
Schieber, Brian
Greg Mitchell, B.
author_facet Mendoza, Wilson G.
Weiss, Elliot L.
Schieber, Brian
Greg Mitchell, B.
author_sort Mendoza, Wilson G.
collection PubMed
description In this study we used fluorescence excitation and emission matrix spectroscopy, hydrographic data, and a self‐organizing map (SOM) analysis to assess the spatial distribution of labile and refractory fluorescent dissolved organic matter (FDOM) for the Chukchi and Beaufort Seas at the time of a massive under‐ice phytoplankton bloom during early summer 2011. Biogeochemical properties were assessed through decomposition of water property classes and sample classification that employed a SOM neural network‐based analysis which classified 10 clusters from 269 samples and 17 variables. The terrestrial, humic‐like component FDOM (ArC1, 4.98 ± 1.54 Quinine Sulfate Units (QSU)) and protein‐like component FDOM (ArC3, 1.63 ± 0.88 QSU) were found to have elevated fluorescence in the Lower Polar Mixed Layer (LPML) (salinity ~29.56 ± 0.76). In the LPML water mass, the observed contribution of meteoric water fraction was 17%, relative to a 12% contribution from the sea ice melt fraction. The labile ArC3‐protein‐like component (2.01 ± 1.92 QSU) was also observed to be elevated in the Pacific Winter Waters mass, where the under‐ice algal bloom was observed (~40–50 m). We interpreted these relationships to indicate that the accumulation and variable distribution of the protein‐like component on the shelf could be influenced directly by sea ice melt, transport, and mixing processes and indirectly by the in situ algal bloom and microbial activity. ArC5, corresponding to what is commonly considered marine humic FDOM, indicated a bimodal distribution with high values in both the freshest and saltiest waters. The association of ArC5 with deep, dense salty water is consistent with this component as refractory humic‐like FDOM, whereas our evidence of a terrestrial origin challenges this classic paradigm for this component.
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spelling pubmed-56065072017-10-05 Controls on the distribution of fluorescent dissolved organic matter during an under‐ice algal bloom in the western Arctic Ocean Mendoza, Wilson G. Weiss, Elliot L. Schieber, Brian Greg Mitchell, B. Global Biogeochem Cycles Research Articles In this study we used fluorescence excitation and emission matrix spectroscopy, hydrographic data, and a self‐organizing map (SOM) analysis to assess the spatial distribution of labile and refractory fluorescent dissolved organic matter (FDOM) for the Chukchi and Beaufort Seas at the time of a massive under‐ice phytoplankton bloom during early summer 2011. Biogeochemical properties were assessed through decomposition of water property classes and sample classification that employed a SOM neural network‐based analysis which classified 10 clusters from 269 samples and 17 variables. The terrestrial, humic‐like component FDOM (ArC1, 4.98 ± 1.54 Quinine Sulfate Units (QSU)) and protein‐like component FDOM (ArC3, 1.63 ± 0.88 QSU) were found to have elevated fluorescence in the Lower Polar Mixed Layer (LPML) (salinity ~29.56 ± 0.76). In the LPML water mass, the observed contribution of meteoric water fraction was 17%, relative to a 12% contribution from the sea ice melt fraction. The labile ArC3‐protein‐like component (2.01 ± 1.92 QSU) was also observed to be elevated in the Pacific Winter Waters mass, where the under‐ice algal bloom was observed (~40–50 m). We interpreted these relationships to indicate that the accumulation and variable distribution of the protein‐like component on the shelf could be influenced directly by sea ice melt, transport, and mixing processes and indirectly by the in situ algal bloom and microbial activity. ArC5, corresponding to what is commonly considered marine humic FDOM, indicated a bimodal distribution with high values in both the freshest and saltiest waters. The association of ArC5 with deep, dense salty water is consistent with this component as refractory humic‐like FDOM, whereas our evidence of a terrestrial origin challenges this classic paradigm for this component. John Wiley and Sons Inc. 2017-07-12 2017-07 /pmc/articles/PMC5606507/ /pubmed/28989231 http://dx.doi.org/10.1002/2016GB005569 Text en ©2017. The Authors. This is an open access article under the terms of the Creative Commons Attribution‐NonCommercial‐NoDerivs (http://creativecommons.org/licenses/by-nc-nd/4.0/) License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non‐commercial and no modifications or adaptations are made.
spellingShingle Research Articles
Mendoza, Wilson G.
Weiss, Elliot L.
Schieber, Brian
Greg Mitchell, B.
Controls on the distribution of fluorescent dissolved organic matter during an under‐ice algal bloom in the western Arctic Ocean
title Controls on the distribution of fluorescent dissolved organic matter during an under‐ice algal bloom in the western Arctic Ocean
title_full Controls on the distribution of fluorescent dissolved organic matter during an under‐ice algal bloom in the western Arctic Ocean
title_fullStr Controls on the distribution of fluorescent dissolved organic matter during an under‐ice algal bloom in the western Arctic Ocean
title_full_unstemmed Controls on the distribution of fluorescent dissolved organic matter during an under‐ice algal bloom in the western Arctic Ocean
title_short Controls on the distribution of fluorescent dissolved organic matter during an under‐ice algal bloom in the western Arctic Ocean
title_sort controls on the distribution of fluorescent dissolved organic matter during an under‐ice algal bloom in the western arctic ocean
topic Research Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5606507/
https://www.ncbi.nlm.nih.gov/pubmed/28989231
http://dx.doi.org/10.1002/2016GB005569
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