Rapid biological oxidation of methanol in the tropical Atlantic: significance as a microbial carbon source
Methanol is the second most abundant organic gas in the atmosphere after methane, and is ubiquitous in the troposphere. It plays a significant role in atmospheric oxidant chemistry and is biogeochemically active. Large uncertainties exist about whether the oceans are a source or sink of methanol to...
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ftcopernicus:oai:publications.copernicus.org:bg11211 2023-05-15T17:35:19+02:00 Rapid biological oxidation of methanol in the tropical Atlantic: significance as a microbial carbon source Dixon, J. L. Beale, R. Nightingale, P. D. 2018-09-27 application/pdf https://doi.org/10.5194/bg-8-2707-2011 https://www.biogeosciences.net/8/2707/2011/ eng eng doi:10.5194/bg-8-2707-2011 https://www.biogeosciences.net/8/2707/2011/ eISSN: 1726-4189 Text 2018 ftcopernicus https://doi.org/10.5194/bg-8-2707-2011 2019-12-24T09:56:39Z Methanol is the second most abundant organic gas in the atmosphere after methane, and is ubiquitous in the troposphere. It plays a significant role in atmospheric oxidant chemistry and is biogeochemically active. Large uncertainties exist about whether the oceans are a source or sink of methanol to the atmosphere. Even less is understood about what reactions in seawater determine its concentration, and hence flux across the sea surface interface. We report here concentrations of methanol between 151–296 nM in parts of the oligotrophic North Atlantic, with corresponding microbial uptake rates between 2–146 nM d −1 , suggesting turnover times as low as 1 day (1–25 days) in surface waters of the oligotrophic tropical North East Atlantic. Methanol is mainly (≥97%) used by microbes for obtaining energy in oligotrophic regions, which contrasts with shelf and coastal areas where between 20–50% can be used for cell growth. Comparisons of microbial methanol oxidation rates with parallel determinations of bacterial leucine uptake suggest that methanol contributes on average 13% to bacterial carbon demand in the central northern Atlantic gyre (maximum of 54%). In addition, the contribution that methanol makes to bacterial carbon demand varies as a power function of chlorophyll a concentrations; suggesting for concentrations <0.2 μg l −1 that methanol can make a significant contribution to bacterial carbon demand. However, our low air to sea methanol flux estimates of 7.2–13 μmol m −2 d −1 suggest that the atmosphere is not a major methanol source. We conclude that there must be a major, as yet unidentified, in situ oceanic methanol source in these latitudes which we suggest is sunlight driven decomposition of organic matter. Text North Atlantic North East Atlantic Copernicus Publications: E-Journals Biogeosciences 8 9 2707 2716 |
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Copernicus Publications: E-Journals |
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English |
description |
Methanol is the second most abundant organic gas in the atmosphere after methane, and is ubiquitous in the troposphere. It plays a significant role in atmospheric oxidant chemistry and is biogeochemically active. Large uncertainties exist about whether the oceans are a source or sink of methanol to the atmosphere. Even less is understood about what reactions in seawater determine its concentration, and hence flux across the sea surface interface. We report here concentrations of methanol between 151–296 nM in parts of the oligotrophic North Atlantic, with corresponding microbial uptake rates between 2–146 nM d −1 , suggesting turnover times as low as 1 day (1–25 days) in surface waters of the oligotrophic tropical North East Atlantic. Methanol is mainly (≥97%) used by microbes for obtaining energy in oligotrophic regions, which contrasts with shelf and coastal areas where between 20–50% can be used for cell growth. Comparisons of microbial methanol oxidation rates with parallel determinations of bacterial leucine uptake suggest that methanol contributes on average 13% to bacterial carbon demand in the central northern Atlantic gyre (maximum of 54%). In addition, the contribution that methanol makes to bacterial carbon demand varies as a power function of chlorophyll a concentrations; suggesting for concentrations <0.2 μg l −1 that methanol can make a significant contribution to bacterial carbon demand. However, our low air to sea methanol flux estimates of 7.2–13 μmol m −2 d −1 suggest that the atmosphere is not a major methanol source. We conclude that there must be a major, as yet unidentified, in situ oceanic methanol source in these latitudes which we suggest is sunlight driven decomposition of organic matter. |
format |
Text |
author |
Dixon, J. L. Beale, R. Nightingale, P. D. |
spellingShingle |
Dixon, J. L. Beale, R. Nightingale, P. D. Rapid biological oxidation of methanol in the tropical Atlantic: significance as a microbial carbon source |
author_facet |
Dixon, J. L. Beale, R. Nightingale, P. D. |
author_sort |
Dixon, J. L. |
title |
Rapid biological oxidation of methanol in the tropical Atlantic: significance as a microbial carbon source |
title_short |
Rapid biological oxidation of methanol in the tropical Atlantic: significance as a microbial carbon source |
title_full |
Rapid biological oxidation of methanol in the tropical Atlantic: significance as a microbial carbon source |
title_fullStr |
Rapid biological oxidation of methanol in the tropical Atlantic: significance as a microbial carbon source |
title_full_unstemmed |
Rapid biological oxidation of methanol in the tropical Atlantic: significance as a microbial carbon source |
title_sort |
rapid biological oxidation of methanol in the tropical atlantic: significance as a microbial carbon source |
publishDate |
2018 |
url |
https://doi.org/10.5194/bg-8-2707-2011 https://www.biogeosciences.net/8/2707/2011/ |
genre |
North Atlantic North East Atlantic |
genre_facet |
North Atlantic North East Atlantic |
op_source |
eISSN: 1726-4189 |
op_relation |
doi:10.5194/bg-8-2707-2011 https://www.biogeosciences.net/8/2707/2011/ |
op_doi |
https://doi.org/10.5194/bg-8-2707-2011 |
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Biogeosciences |
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8 |
container_issue |
9 |
container_start_page |
2707 |
op_container_end_page |
2716 |
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1766134441444376576 |