Sea-suface microlayer (SML) and underlying water (ULW) samples focusing on CDOM spectral characteristics during METEOR cruise M91, supplement to: Galgani, Luisa; Engel, Anja (2016): Changes in optical characteristics of surface microlayers hint to photochemically and microbially mediated DOM turnover in the upwelling region off the coast of Peru. Biogeosciences, 13(8), 2453-2473
The coastal upwelling system off the coast of Peru is characterized by high biological activity and a pronounced subsurface oxygen minimum zone, as well as associated emissions of atmospheric trace gases such as N2O, CH4 and CO2. From 3 to 23 December 2012, R/V Meteor (M91) cruise took place in the...
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Language: | English |
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PANGAEA - Data Publisher for Earth & Environmental Science
2016
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Online Access: | https://dx.doi.org/10.1594/pangaea.861947 https://doi.pangaea.de/10.1594/PANGAEA.861947 |
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ftdatacite:10.1594/pangaea.861947 |
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openpolar |
institution |
Open Polar |
collection |
DataCite Metadata Store (German National Library of Science and Technology) |
op_collection_id |
ftdatacite |
language |
English |
topic |
Event label Comment Sample ID Sample type Date/Time of event LATITUDE LONGITUDE Salinity Temperature, water Radiation, photosynthetically active Wind speed Radiogenic heat production Fluorescence, dissolved organic matter, component Amino acids, dissolved hydrolyzable Transparent exopolymer particles, abundance Coomassie stainable particles, abundance Spectral slope of colored dissolved organic matter absorption, 300-500 nm Absorption coefficient, colored dissolved organic matter at 325 nm Humification index Specific ultraviolet absorbance per mass Carbon Slope ratio Bacteria Phytoplankton Carbon, organic, dissolved Carbon, organic, particulate Rubber boat, Zodiac M91 Meteor 1986 Biological Impacts of Ocean Acidification BIOACID |
spellingShingle |
Event label Comment Sample ID Sample type Date/Time of event LATITUDE LONGITUDE Salinity Temperature, water Radiation, photosynthetically active Wind speed Radiogenic heat production Fluorescence, dissolved organic matter, component Amino acids, dissolved hydrolyzable Transparent exopolymer particles, abundance Coomassie stainable particles, abundance Spectral slope of colored dissolved organic matter absorption, 300-500 nm Absorption coefficient, colored dissolved organic matter at 325 nm Humification index Specific ultraviolet absorbance per mass Carbon Slope ratio Bacteria Phytoplankton Carbon, organic, dissolved Carbon, organic, particulate Rubber boat, Zodiac M91 Meteor 1986 Biological Impacts of Ocean Acidification BIOACID Galgani, Luisa Engel, Anja Sea-suface microlayer (SML) and underlying water (ULW) samples focusing on CDOM spectral characteristics during METEOR cruise M91, supplement to: Galgani, Luisa; Engel, Anja (2016): Changes in optical characteristics of surface microlayers hint to photochemically and microbially mediated DOM turnover in the upwelling region off the coast of Peru. Biogeosciences, 13(8), 2453-2473 |
topic_facet |
Event label Comment Sample ID Sample type Date/Time of event LATITUDE LONGITUDE Salinity Temperature, water Radiation, photosynthetically active Wind speed Radiogenic heat production Fluorescence, dissolved organic matter, component Amino acids, dissolved hydrolyzable Transparent exopolymer particles, abundance Coomassie stainable particles, abundance Spectral slope of colored dissolved organic matter absorption, 300-500 nm Absorption coefficient, colored dissolved organic matter at 325 nm Humification index Specific ultraviolet absorbance per mass Carbon Slope ratio Bacteria Phytoplankton Carbon, organic, dissolved Carbon, organic, particulate Rubber boat, Zodiac M91 Meteor 1986 Biological Impacts of Ocean Acidification BIOACID |
description |
The coastal upwelling system off the coast of Peru is characterized by high biological activity and a pronounced subsurface oxygen minimum zone, as well as associated emissions of atmospheric trace gases such as N2O, CH4 and CO2. From 3 to 23 December 2012, R/V Meteor (M91) cruise took place in the Peruvian upwelling system between 4.59 and 15.4°S, and 82.0 to 77.5°W. During M91 we investigated the composition of the sea-surface microlayer (SML), the oceanic uppermost boundary directly subject to high solar radiation, often enriched in specific organic compounds of biological origin like chromophoric dissolved organic matter (CDOM) and marine gels. In the SML, the continuous photochemical and microbial recycling of organic matter may strongly influence gas exchange between marine systems and the atmosphere. We analyzed SML and underlying water (ULW) samples at 38 stations focusing on CDOM spectral characteristics as indicator of photochemical and microbial alteration processes. CDOM composition was characterized by spectral slope (S) values and excitation-emission matrix fluorescence (EEMs), which allow us to track changes in molecular weight (MW) of DOM, and to determine potential DOM sources and sinks. Spectral slope S varied between 0.012 to 0.043 1 nm-1 and was quite similar between SML and ULW, with no significant differences between the two compartments. Higher S values were observed in the ULW of the southern stations below 15°S. By EEMs, we identified five fluorescent components (F1-5) of the CDOM pool, of which two had excitation/emission characteristics of amino-acid-like fluorophores (F1, F4) and were highly enriched in the SML, with a median ratio SML : ULW of 1.5 for both fluorophores. In the study region, values for CDOM absorption ranged from 0.07 to 1.47 m-1. CDOM was generally highly concentrated in the SML, with a median enrichment with respect to the ULW of 1.2. CDOM composition and changes in spectral slope properties suggested a local microbial release of DOM directly in the SML as a response to light exposure in this extreme environment. In a conceptual model of the sources and modifications of optically active DOM in the SML and underlying seawater (ULW), we describe processes we think may take place (Fig. 1); the production of CDOM of higher MW by microbial release through growth, exudation and lysis in the euphotic zone, includes the identified fluorophores (F1, F2, F3, F4, F5). Specific amino-acid-like fluorophores (F1, F4) accumulate in the SML with respect to the ULW, as photochemistry may enhance microbial CDOM release by (a) photoprotection mechanisms and (b) cell-lysis processes. Microbial and photochemical degradation are potential sinks of the amino-acid-like fluorophores (F1, F4), and potential sources of reworked and more refractory humic-like components (F2, F3, F5). In the highly productive upwelling region along the Peruvian coast, the interplay of microbial and photochemical processes controls the enrichment of amino-acid-like CDOM in the SML. We discuss potential implications for air-sea gas exchange in this area. |
format |
Dataset |
author |
Galgani, Luisa Engel, Anja |
author_facet |
Galgani, Luisa Engel, Anja |
author_sort |
Galgani, Luisa |
title |
Sea-suface microlayer (SML) and underlying water (ULW) samples focusing on CDOM spectral characteristics during METEOR cruise M91, supplement to: Galgani, Luisa; Engel, Anja (2016): Changes in optical characteristics of surface microlayers hint to photochemically and microbially mediated DOM turnover in the upwelling region off the coast of Peru. Biogeosciences, 13(8), 2453-2473 |
title_short |
Sea-suface microlayer (SML) and underlying water (ULW) samples focusing on CDOM spectral characteristics during METEOR cruise M91, supplement to: Galgani, Luisa; Engel, Anja (2016): Changes in optical characteristics of surface microlayers hint to photochemically and microbially mediated DOM turnover in the upwelling region off the coast of Peru. Biogeosciences, 13(8), 2453-2473 |
title_full |
Sea-suface microlayer (SML) and underlying water (ULW) samples focusing on CDOM spectral characteristics during METEOR cruise M91, supplement to: Galgani, Luisa; Engel, Anja (2016): Changes in optical characteristics of surface microlayers hint to photochemically and microbially mediated DOM turnover in the upwelling region off the coast of Peru. Biogeosciences, 13(8), 2453-2473 |
title_fullStr |
Sea-suface microlayer (SML) and underlying water (ULW) samples focusing on CDOM spectral characteristics during METEOR cruise M91, supplement to: Galgani, Luisa; Engel, Anja (2016): Changes in optical characteristics of surface microlayers hint to photochemically and microbially mediated DOM turnover in the upwelling region off the coast of Peru. Biogeosciences, 13(8), 2453-2473 |
title_full_unstemmed |
Sea-suface microlayer (SML) and underlying water (ULW) samples focusing on CDOM spectral characteristics during METEOR cruise M91, supplement to: Galgani, Luisa; Engel, Anja (2016): Changes in optical characteristics of surface microlayers hint to photochemically and microbially mediated DOM turnover in the upwelling region off the coast of Peru. Biogeosciences, 13(8), 2453-2473 |
title_sort |
sea-suface microlayer (sml) and underlying water (ulw) samples focusing on cdom spectral characteristics during meteor cruise m91, supplement to: galgani, luisa; engel, anja (2016): changes in optical characteristics of surface microlayers hint to photochemically and microbially mediated dom turnover in the upwelling region off the coast of peru. biogeosciences, 13(8), 2453-2473 |
publisher |
PANGAEA - Data Publisher for Earth & Environmental Science |
publishDate |
2016 |
url |
https://dx.doi.org/10.1594/pangaea.861947 https://doi.pangaea.de/10.1594/PANGAEA.861947 |
long_lat |
ENVELOPE(-62.376,-62.376,-64.605,-64.605) |
geographic |
Luisa |
geographic_facet |
Luisa |
genre |
Ocean acidification |
genre_facet |
Ocean acidification |
op_relation |
https://dx.doi.org/10.5194/bg-13-2453-2016 https://dx.doi.org/10.5194/bg-13-989-2016 https://dx.doi.org/10.1594/pangaea.859853 |
op_rights |
Creative Commons Attribution 3.0 Unported https://creativecommons.org/licenses/by/3.0/legalcode cc-by-3.0 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1594/pangaea.861947 https://doi.org/10.5194/bg-13-2453-2016 https://doi.org/10.5194/bg-13-989-2016 https://doi.org/10.1594/pangaea.859853 |
_version_ |
1766159640497750016 |
spelling |
ftdatacite:10.1594/pangaea.861947 2023-05-15T17:52:15+02:00 Sea-suface microlayer (SML) and underlying water (ULW) samples focusing on CDOM spectral characteristics during METEOR cruise M91, supplement to: Galgani, Luisa; Engel, Anja (2016): Changes in optical characteristics of surface microlayers hint to photochemically and microbially mediated DOM turnover in the upwelling region off the coast of Peru. Biogeosciences, 13(8), 2453-2473 Galgani, Luisa Engel, Anja 2016 text/tab-separated-values https://dx.doi.org/10.1594/pangaea.861947 https://doi.pangaea.de/10.1594/PANGAEA.861947 en eng PANGAEA - Data Publisher for Earth & Environmental Science https://dx.doi.org/10.5194/bg-13-2453-2016 https://dx.doi.org/10.5194/bg-13-989-2016 https://dx.doi.org/10.1594/pangaea.859853 Creative Commons Attribution 3.0 Unported https://creativecommons.org/licenses/by/3.0/legalcode cc-by-3.0 CC-BY Event label Comment Sample ID Sample type Date/Time of event LATITUDE LONGITUDE Salinity Temperature, water Radiation, photosynthetically active Wind speed Radiogenic heat production Fluorescence, dissolved organic matter, component Amino acids, dissolved hydrolyzable Transparent exopolymer particles, abundance Coomassie stainable particles, abundance Spectral slope of colored dissolved organic matter absorption, 300-500 nm Absorption coefficient, colored dissolved organic matter at 325 nm Humification index Specific ultraviolet absorbance per mass Carbon Slope ratio Bacteria Phytoplankton Carbon, organic, dissolved Carbon, organic, particulate Rubber boat, Zodiac M91 Meteor 1986 Biological Impacts of Ocean Acidification BIOACID Dataset dataset Supplementary Dataset 2016 ftdatacite https://doi.org/10.1594/pangaea.861947 https://doi.org/10.5194/bg-13-2453-2016 https://doi.org/10.5194/bg-13-989-2016 https://doi.org/10.1594/pangaea.859853 2022-02-09T13:13:43Z The coastal upwelling system off the coast of Peru is characterized by high biological activity and a pronounced subsurface oxygen minimum zone, as well as associated emissions of atmospheric trace gases such as N2O, CH4 and CO2. From 3 to 23 December 2012, R/V Meteor (M91) cruise took place in the Peruvian upwelling system between 4.59 and 15.4°S, and 82.0 to 77.5°W. During M91 we investigated the composition of the sea-surface microlayer (SML), the oceanic uppermost boundary directly subject to high solar radiation, often enriched in specific organic compounds of biological origin like chromophoric dissolved organic matter (CDOM) and marine gels. In the SML, the continuous photochemical and microbial recycling of organic matter may strongly influence gas exchange between marine systems and the atmosphere. We analyzed SML and underlying water (ULW) samples at 38 stations focusing on CDOM spectral characteristics as indicator of photochemical and microbial alteration processes. CDOM composition was characterized by spectral slope (S) values and excitation-emission matrix fluorescence (EEMs), which allow us to track changes in molecular weight (MW) of DOM, and to determine potential DOM sources and sinks. Spectral slope S varied between 0.012 to 0.043 1 nm-1 and was quite similar between SML and ULW, with no significant differences between the two compartments. Higher S values were observed in the ULW of the southern stations below 15°S. By EEMs, we identified five fluorescent components (F1-5) of the CDOM pool, of which two had excitation/emission characteristics of amino-acid-like fluorophores (F1, F4) and were highly enriched in the SML, with a median ratio SML : ULW of 1.5 for both fluorophores. In the study region, values for CDOM absorption ranged from 0.07 to 1.47 m-1. CDOM was generally highly concentrated in the SML, with a median enrichment with respect to the ULW of 1.2. CDOM composition and changes in spectral slope properties suggested a local microbial release of DOM directly in the SML as a response to light exposure in this extreme environment. In a conceptual model of the sources and modifications of optically active DOM in the SML and underlying seawater (ULW), we describe processes we think may take place (Fig. 1); the production of CDOM of higher MW by microbial release through growth, exudation and lysis in the euphotic zone, includes the identified fluorophores (F1, F2, F3, F4, F5). Specific amino-acid-like fluorophores (F1, F4) accumulate in the SML with respect to the ULW, as photochemistry may enhance microbial CDOM release by (a) photoprotection mechanisms and (b) cell-lysis processes. Microbial and photochemical degradation are potential sinks of the amino-acid-like fluorophores (F1, F4), and potential sources of reworked and more refractory humic-like components (F2, F3, F5). In the highly productive upwelling region along the Peruvian coast, the interplay of microbial and photochemical processes controls the enrichment of amino-acid-like CDOM in the SML. We discuss potential implications for air-sea gas exchange in this area. Dataset Ocean acidification DataCite Metadata Store (German National Library of Science and Technology) Luisa ENVELOPE(-62.376,-62.376,-64.605,-64.605) |