Measurements of methyl chloride in the Northwest Atlantic
Methyl chloride was measured directly in seawater using a purge and trap system and gas chromatography with electron capture detection. The results indicate that surface waters of the northwest Atlantic are a source of methyl chloride to the atmosphere during late spring/early summer. The average su...
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Online Access: | http://hdl.handle.net/10222/27174 https://doi.org/10.1029/93JC03582 |
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ftdalhouse:oai:DalSpace.library.dal.ca:10222/27174 2023-05-15T17:45:34+02:00 Measurements of methyl chloride in the Northwest Atlantic Tait, V. K. Moore, R. M. Tokarczyk, R. 2013-06-19T18:02:28Z http://hdl.handle.net/10222/27174 https://doi.org/10.1029/93JC03582 en eng American Geophysical Union Journal of Geophysical Research.C.Oceans Tait, V. K., R. M. Moore, and R. Tokarczyk. 1994. "Measurements of methyl chloride in the Northwest Atlantic." Journal of Geophysical Research.C.Oceans 99(C4): 7821-7833. DOI:10.1029/93JC03582 0148-0227 http://hdl.handle.net/10222/27174 http://dx.doi.org/10.1029/93JC03582 99 4 7821 This paper was published by AGU. Copyright 1994 American Geophysical Union Chlorophylls Shelf edge Surface water Chlorides Phytoplankton Chloride Primary production Atmosphere Marine environment Gas chromatography Boundary layer mixing Atmospheric gases Data processing Chlorine compounds Methyl chloride Troposphere Seasonal thermocline Chemical oceanography Phytoplankton production Boundary layers Oceans Thermocline article 2013 ftdalhouse https://doi.org/10.1029/93JC03582 2021-12-29T18:08:42Z Methyl chloride was measured directly in seawater using a purge and trap system and gas chromatography with electron capture detection. The results indicate that surface waters of the northwest Atlantic are a source of methyl chloride to the atmosphere during late spring/early summer. The average surface concentration was 271 pM ( sigma = 68 pM), supersaturated with respect to an assumed tropospheric boundary layer mixing ratio of 0.7 ppbv. Elevated concentrations were observed throughout the region in waters above the seasonal thermocline. Near-surface maxima of differing thickness and intensity were also seen within this upper layer. Broad maxima within the 200-800m depth range were associated with water masses more recently subducted from the surface than the surrounding main thermocline waters. Coastal inputs of methyl chloride appear not to be an important source in the area of study. Although there is some indication of elevated concentrations associated with higher phytoplankton activity in shelf edge regions, the picture concerning phytoplankton production of methyl chloride is still unclear. Further work is required to look at direct and indirect mechanisms by which phytoplankton may influence the distribution of methyl chloride in the oceans. The global ocean-to-atmosphere flux estimated from this data set, 3.3-4.8 x 10 super(10) mol CH sub(3)Cl/yr (1.7-2.4 x 10 super(12) g CH sub(3)Cl/yr) suggests that the oceans may contribute a smaller flux of methyl chloride to the atmosphere than previously thought. Article in Journal/Newspaper Northwest Atlantic Dalhousie University: DalSpace Institutional Repository Journal of Geophysical Research 99 C4 7821 |
institution |
Open Polar |
collection |
Dalhousie University: DalSpace Institutional Repository |
op_collection_id |
ftdalhouse |
language |
English |
topic |
Chlorophylls Shelf edge Surface water Chlorides Phytoplankton Chloride Primary production Atmosphere Marine environment Gas chromatography Boundary layer mixing Atmospheric gases Data processing Chlorine compounds Methyl chloride Troposphere Seasonal thermocline Chemical oceanography Phytoplankton production Boundary layers Oceans Thermocline |
spellingShingle |
Chlorophylls Shelf edge Surface water Chlorides Phytoplankton Chloride Primary production Atmosphere Marine environment Gas chromatography Boundary layer mixing Atmospheric gases Data processing Chlorine compounds Methyl chloride Troposphere Seasonal thermocline Chemical oceanography Phytoplankton production Boundary layers Oceans Thermocline Tait, V. K. Moore, R. M. Tokarczyk, R. Measurements of methyl chloride in the Northwest Atlantic |
topic_facet |
Chlorophylls Shelf edge Surface water Chlorides Phytoplankton Chloride Primary production Atmosphere Marine environment Gas chromatography Boundary layer mixing Atmospheric gases Data processing Chlorine compounds Methyl chloride Troposphere Seasonal thermocline Chemical oceanography Phytoplankton production Boundary layers Oceans Thermocline |
description |
Methyl chloride was measured directly in seawater using a purge and trap system and gas chromatography with electron capture detection. The results indicate that surface waters of the northwest Atlantic are a source of methyl chloride to the atmosphere during late spring/early summer. The average surface concentration was 271 pM ( sigma = 68 pM), supersaturated with respect to an assumed tropospheric boundary layer mixing ratio of 0.7 ppbv. Elevated concentrations were observed throughout the region in waters above the seasonal thermocline. Near-surface maxima of differing thickness and intensity were also seen within this upper layer. Broad maxima within the 200-800m depth range were associated with water masses more recently subducted from the surface than the surrounding main thermocline waters. Coastal inputs of methyl chloride appear not to be an important source in the area of study. Although there is some indication of elevated concentrations associated with higher phytoplankton activity in shelf edge regions, the picture concerning phytoplankton production of methyl chloride is still unclear. Further work is required to look at direct and indirect mechanisms by which phytoplankton may influence the distribution of methyl chloride in the oceans. The global ocean-to-atmosphere flux estimated from this data set, 3.3-4.8 x 10 super(10) mol CH sub(3)Cl/yr (1.7-2.4 x 10 super(12) g CH sub(3)Cl/yr) suggests that the oceans may contribute a smaller flux of methyl chloride to the atmosphere than previously thought. |
format |
Article in Journal/Newspaper |
author |
Tait, V. K. Moore, R. M. Tokarczyk, R. |
author_facet |
Tait, V. K. Moore, R. M. Tokarczyk, R. |
author_sort |
Tait, V. K. |
title |
Measurements of methyl chloride in the Northwest Atlantic |
title_short |
Measurements of methyl chloride in the Northwest Atlantic |
title_full |
Measurements of methyl chloride in the Northwest Atlantic |
title_fullStr |
Measurements of methyl chloride in the Northwest Atlantic |
title_full_unstemmed |
Measurements of methyl chloride in the Northwest Atlantic |
title_sort |
measurements of methyl chloride in the northwest atlantic |
publisher |
American Geophysical Union |
publishDate |
2013 |
url |
http://hdl.handle.net/10222/27174 https://doi.org/10.1029/93JC03582 |
genre |
Northwest Atlantic |
genre_facet |
Northwest Atlantic |
op_relation |
Journal of Geophysical Research.C.Oceans Tait, V. K., R. M. Moore, and R. Tokarczyk. 1994. "Measurements of methyl chloride in the Northwest Atlantic." Journal of Geophysical Research.C.Oceans 99(C4): 7821-7833. DOI:10.1029/93JC03582 0148-0227 http://hdl.handle.net/10222/27174 http://dx.doi.org/10.1029/93JC03582 99 4 7821 |
op_rights |
This paper was published by AGU. Copyright 1994 American Geophysical Union |
op_doi |
https://doi.org/10.1029/93JC03582 |
container_title |
Journal of Geophysical Research |
container_volume |
99 |
container_issue |
C4 |
container_start_page |
7821 |
_version_ |
1766148686672297984 |