2,000-year record of atmospheric methyl bromide from a South Pole ice core
This study reports measurements of methyl bromide (CH3Br) in air bubbles from a South Pole ice core, with gas ages covering the past two millennia. The air was extracted by mechanical shredding of the core under vacuum and the evolved gases were analyzed by gas chromatography with high resolution ma...
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Language: | English |
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ftcdlib:qt60h2n397 2023-05-15T13:54:07+02:00 2,000-year record of atmospheric methyl bromide from a South Pole ice core Saltzman, Eric S Aydin, Murat Tatum, Cheryl Williams, Margaret B n/a - n/a 2008-03-01 application/pdf http://www.escholarship.org/uc/item/60h2n397 english eng eScholarship, University of California qt60h2n397 http://www.escholarship.org/uc/item/60h2n397 Attribution (CC BY): http://creativecommons.org/licenses/by/3.0/ CC-BY Saltzman, Eric S; Aydin, Murat; Tatum, Cheryl; & Williams, Margaret B. (2008). 2,000-year record of atmospheric methyl bromide from a South Pole ice core. Journal of Geophysical Research: Atmospheres, 113(D5), n/a - n/a. doi:10.1029/2007JD008919. UC Irvine: Department of Earth System Science, UCI. Retrieved from: http://www.escholarship.org/uc/item/60h2n397 Physical Sciences and Mathematics dilution gas chromatography ice isotopes mass spectrometry ozone air bubble ice core industrialization methyl bromide mixing ratio southern hemisphere temporal variation trend analysis twentieth century Antarctica East Antarctica South Pole article 2008 ftcdlib https://doi.org/10.1029/2007JD008919 2016-04-02T18:40:04Z This study reports measurements of methyl bromide (CH3Br) in air bubbles from a South Pole ice core, with gas ages covering the past two millennia. The air was extracted by mechanical shredding of the core under vacuum and the evolved gases were analyzed by gas chromatography with high resolution mass spectrometry and isotope dilution. These samples had estimated mean gas ages ranging from 160 BCE to 1860 CE. The mean CH3Br mixing ratio in the ice core samples was 5.39 ±.06 ppt (1s.e., n = 113). The CH3Br measurements from this core agree with those from a Siple Dome ice core for mean gas ages between 1671 and 1860 CE, where there is overlap between the cores. The data show no linear trend over the 2000 year period prior to industrialization. Together, Antarctic ice core and firn air measurements clearly demonstrate that the increase in atmospheric CH3Br during the twentieth century exceeds natural variability during the past 2000 years. There is evidence of centennial-scale variability in CH3Br on the order of ±10–20% that may indicate a natural climate sensitivity of the atmospheric levels of this ozone depleting substance. The analysis of CH3Br in additional Antarctic ice cores will be needed to confirm that the centennial-scale variability observed in this core represents a southern hemisphere atmospheric history. Article in Journal/Newspaper Antarc* Antarctic Antarctica East Antarctica ice core South pole South pole University of California: eScholarship Antarctic East Antarctica Siple ENVELOPE(-83.917,-83.917,-75.917,-75.917) Siple Dome ENVELOPE(-148.833,-148.833,-81.667,-81.667) South Pole Journal of Geophysical Research: Atmospheres 113 D5 n/a n/a |
institution |
Open Polar |
collection |
University of California: eScholarship |
op_collection_id |
ftcdlib |
language |
English |
topic |
Physical Sciences and Mathematics dilution gas chromatography ice isotopes mass spectrometry ozone air bubble ice core industrialization methyl bromide mixing ratio southern hemisphere temporal variation trend analysis twentieth century Antarctica East Antarctica South Pole |
spellingShingle |
Physical Sciences and Mathematics dilution gas chromatography ice isotopes mass spectrometry ozone air bubble ice core industrialization methyl bromide mixing ratio southern hemisphere temporal variation trend analysis twentieth century Antarctica East Antarctica South Pole Saltzman, Eric S Aydin, Murat Tatum, Cheryl Williams, Margaret B 2,000-year record of atmospheric methyl bromide from a South Pole ice core |
topic_facet |
Physical Sciences and Mathematics dilution gas chromatography ice isotopes mass spectrometry ozone air bubble ice core industrialization methyl bromide mixing ratio southern hemisphere temporal variation trend analysis twentieth century Antarctica East Antarctica South Pole |
description |
This study reports measurements of methyl bromide (CH3Br) in air bubbles from a South Pole ice core, with gas ages covering the past two millennia. The air was extracted by mechanical shredding of the core under vacuum and the evolved gases were analyzed by gas chromatography with high resolution mass spectrometry and isotope dilution. These samples had estimated mean gas ages ranging from 160 BCE to 1860 CE. The mean CH3Br mixing ratio in the ice core samples was 5.39 ±.06 ppt (1s.e., n = 113). The CH3Br measurements from this core agree with those from a Siple Dome ice core for mean gas ages between 1671 and 1860 CE, where there is overlap between the cores. The data show no linear trend over the 2000 year period prior to industrialization. Together, Antarctic ice core and firn air measurements clearly demonstrate that the increase in atmospheric CH3Br during the twentieth century exceeds natural variability during the past 2000 years. There is evidence of centennial-scale variability in CH3Br on the order of ±10–20% that may indicate a natural climate sensitivity of the atmospheric levels of this ozone depleting substance. The analysis of CH3Br in additional Antarctic ice cores will be needed to confirm that the centennial-scale variability observed in this core represents a southern hemisphere atmospheric history. |
format |
Article in Journal/Newspaper |
author |
Saltzman, Eric S Aydin, Murat Tatum, Cheryl Williams, Margaret B |
author_facet |
Saltzman, Eric S Aydin, Murat Tatum, Cheryl Williams, Margaret B |
author_sort |
Saltzman, Eric S |
title |
2,000-year record of atmospheric methyl bromide from a South Pole ice core |
title_short |
2,000-year record of atmospheric methyl bromide from a South Pole ice core |
title_full |
2,000-year record of atmospheric methyl bromide from a South Pole ice core |
title_fullStr |
2,000-year record of atmospheric methyl bromide from a South Pole ice core |
title_full_unstemmed |
2,000-year record of atmospheric methyl bromide from a South Pole ice core |
title_sort |
2,000-year record of atmospheric methyl bromide from a south pole ice core |
publisher |
eScholarship, University of California |
publishDate |
2008 |
url |
http://www.escholarship.org/uc/item/60h2n397 |
op_coverage |
n/a - n/a |
long_lat |
ENVELOPE(-83.917,-83.917,-75.917,-75.917) ENVELOPE(-148.833,-148.833,-81.667,-81.667) |
geographic |
Antarctic East Antarctica Siple Siple Dome South Pole |
geographic_facet |
Antarctic East Antarctica Siple Siple Dome South Pole |
genre |
Antarc* Antarctic Antarctica East Antarctica ice core South pole South pole |
genre_facet |
Antarc* Antarctic Antarctica East Antarctica ice core South pole South pole |
op_source |
Saltzman, Eric S; Aydin, Murat; Tatum, Cheryl; & Williams, Margaret B. (2008). 2,000-year record of atmospheric methyl bromide from a South Pole ice core. Journal of Geophysical Research: Atmospheres, 113(D5), n/a - n/a. doi:10.1029/2007JD008919. UC Irvine: Department of Earth System Science, UCI. Retrieved from: http://www.escholarship.org/uc/item/60h2n397 |
op_relation |
qt60h2n397 http://www.escholarship.org/uc/item/60h2n397 |
op_rights |
Attribution (CC BY): http://creativecommons.org/licenses/by/3.0/ |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1029/2007JD008919 |
container_title |
Journal of Geophysical Research: Atmospheres |
container_volume |
113 |
container_issue |
D5 |
container_start_page |
n/a |
op_container_end_page |
n/a |
_version_ |
1766259774119215104 |