Air-Sea CO 2 -Exchange in a Large Annular Wind-Wave Tank and the Effects of Surfactants
Wind, chemical enhancement, phytoplankton activity, and surfactants are potential factors driving the air-sea gas exchange of carbon dioxide (CO2). We investigated their effects on the gas transfer velocity of CO2 in a large annular wind-wave tank filled with natural seawater from the North Atlantic...
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ftpubman:oai:pure.mpg.de:item_3027778 2023-08-20T04:08:28+02:00 Air-Sea CO 2 -Exchange in a Large Annular Wind-Wave Tank and the Effects of Surfactants Ribas-Ribas, M. Helleis, F. Rahlff, J. Wurl, O. 2018 http://hdl.handle.net/21.11116/0000-0003-02B7-C eng eng info:eu-repo/semantics/altIdentifier/doi/10.3389/fmars.2018.00457 http://hdl.handle.net/21.11116/0000-0003-02B7-C Frontiers in marine science info:eu-repo/semantics/article 2018 ftpubman https://doi.org/10.3389/fmars.2018.00457 2023-08-01T23:48:53Z Wind, chemical enhancement, phytoplankton activity, and surfactants are potential factors driving the air-sea gas exchange of carbon dioxide (CO2). We investigated their effects on the gas transfer velocity of CO2 in a large annular wind-wave tank filled with natural seawater from the North Atlantic Ocean. Experiments were run under 11 different wind speed conditions (ranging from 1.5 ms−1 to 22.8 ms−1), and we increased the water pCO2 concentration twice by more than 950 μatm for two of the seven experimental days. We develop a conceptual box model that incorporated the thermodynamics of the marine CO2 system. Surfactant concentrations in the sea surface microlayer (SML) ranged from 301 to 1015 μgL−1 (as Triton X-100 equivalents) with enrichments ranged from 1.0 to 5.7 in comparison to the samples from the underlying bulk water. With wind speeds up to 8.5 ms−1, surfactants in the SML can reduce the gas transfer velocity by 54%. Wind-wave tank experiments in combination with modeling are useful tools for obtaining a better understanding of the gas transfer velocities of CO2 across the air-sea boundary. The tank allowed for measuring the gas exchange velocity under extreme low and high wind speeds; in contrast, most previous parametrizations have fallen short because measurements of gas exchange velocities in the field are challenging, especially at low wind conditions. High variability in the CO2 transfer velocities suggests that gas exchange is a complex process not solely controlled by wind forces, especially in low wind conditions. Article in Journal/Newspaper North Atlantic Max Planck Society: MPG.PuRe Triton ENVELOPE(-55.615,-55.615,49.517,49.517) Frontiers in Marine Science 5 |
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Max Planck Society: MPG.PuRe |
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ftpubman |
language |
English |
description |
Wind, chemical enhancement, phytoplankton activity, and surfactants are potential factors driving the air-sea gas exchange of carbon dioxide (CO2). We investigated their effects on the gas transfer velocity of CO2 in a large annular wind-wave tank filled with natural seawater from the North Atlantic Ocean. Experiments were run under 11 different wind speed conditions (ranging from 1.5 ms−1 to 22.8 ms−1), and we increased the water pCO2 concentration twice by more than 950 μatm for two of the seven experimental days. We develop a conceptual box model that incorporated the thermodynamics of the marine CO2 system. Surfactant concentrations in the sea surface microlayer (SML) ranged from 301 to 1015 μgL−1 (as Triton X-100 equivalents) with enrichments ranged from 1.0 to 5.7 in comparison to the samples from the underlying bulk water. With wind speeds up to 8.5 ms−1, surfactants in the SML can reduce the gas transfer velocity by 54%. Wind-wave tank experiments in combination with modeling are useful tools for obtaining a better understanding of the gas transfer velocities of CO2 across the air-sea boundary. The tank allowed for measuring the gas exchange velocity under extreme low and high wind speeds; in contrast, most previous parametrizations have fallen short because measurements of gas exchange velocities in the field are challenging, especially at low wind conditions. High variability in the CO2 transfer velocities suggests that gas exchange is a complex process not solely controlled by wind forces, especially in low wind conditions. |
format |
Article in Journal/Newspaper |
author |
Ribas-Ribas, M. Helleis, F. Rahlff, J. Wurl, O. |
spellingShingle |
Ribas-Ribas, M. Helleis, F. Rahlff, J. Wurl, O. Air-Sea CO 2 -Exchange in a Large Annular Wind-Wave Tank and the Effects of Surfactants |
author_facet |
Ribas-Ribas, M. Helleis, F. Rahlff, J. Wurl, O. |
author_sort |
Ribas-Ribas, M. |
title |
Air-Sea CO 2 -Exchange in a Large Annular Wind-Wave Tank and the Effects of Surfactants |
title_short |
Air-Sea CO 2 -Exchange in a Large Annular Wind-Wave Tank and the Effects of Surfactants |
title_full |
Air-Sea CO 2 -Exchange in a Large Annular Wind-Wave Tank and the Effects of Surfactants |
title_fullStr |
Air-Sea CO 2 -Exchange in a Large Annular Wind-Wave Tank and the Effects of Surfactants |
title_full_unstemmed |
Air-Sea CO 2 -Exchange in a Large Annular Wind-Wave Tank and the Effects of Surfactants |
title_sort |
air-sea co 2 -exchange in a large annular wind-wave tank and the effects of surfactants |
publishDate |
2018 |
url |
http://hdl.handle.net/21.11116/0000-0003-02B7-C |
long_lat |
ENVELOPE(-55.615,-55.615,49.517,49.517) |
geographic |
Triton |
geographic_facet |
Triton |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Frontiers in marine science |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.3389/fmars.2018.00457 http://hdl.handle.net/21.11116/0000-0003-02B7-C |
op_doi |
https://doi.org/10.3389/fmars.2018.00457 |
container_title |
Frontiers in Marine Science |
container_volume |
5 |
_version_ |
1774720732037644288 |