Direct detection of atmospheric atomic bromine leading to mercury and ozone depletion
Bromine atoms play a central role in atmospheric reactive halogen chemistry, depleting ozone and elemental mercury, thereby enhancing deposition of toxic mercury, particularly in the Arctic near-surface troposphere. However, direct bromine atom measurements have been missing to date, due to the lack...
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2019
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Online Access: | https://doi.org/10.1073/pnas.1900613116 |
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ftncar:oai:drupal-site.org:articles_22666 2023-09-05T13:17:06+02:00 Direct detection of atmospheric atomic bromine leading to mercury and ozone depletion Wang, Siyuan (author) McNamara, Stephen M. (author) Moore, Christopher W. (author) Obrist, Daniel (author) Steffen, Alexandra (author) Shepson, Paul B. (author) Staebler, Ralf M. (author) Raso, Angela R. W. (author) Pratt, Kerri A. (author) 2019-06-28 https://doi.org/10.1073/pnas.1900613116 en eng Proceedings of the National Academy of Sciences--Proc Natl Acad Sci USA--0027-8424--1091-6490 articles:22666 ark:/85065/d7m90csp doi:10.1073/pnas.1900613116 Copyright 2019 Author(s). Published under license by the National Academy of Sciences. article Text 2019 ftncar https://doi.org/10.1073/pnas.1900613116 2023-08-14T18:50:20Z Bromine atoms play a central role in atmospheric reactive halogen chemistry, depleting ozone and elemental mercury, thereby enhancing deposition of toxic mercury, particularly in the Arctic near-surface troposphere. However, direct bromine atom measurements have been missing to date, due to the lack of analytical capability with sufficient sensitivity for ambient measurements. Here we present direct atmospheric bromine atom measurements, conducted in the springtime Arctic. Measured bromine atom levels reached 14 parts per trillion (ppt, pmol mol(-1); 4.2 x 10(8) atoms per cm(-3)) and were up to 3-10 times higher than estimates using previous indirect measurements not considering the critical role of molecular bromine. Observed ozone and elemental mercury depletion rates are quantitatively explained by the measured bromine atoms, providing field validation of highly uncertain mercury chemistry. Following complete ozone depletion, elevated bromine concentrations are sustained by photochemical snowpack emissions of molecular bromine and nitrogen oxides, resulting in continued atmospheric mercury depletion. This study provides a breakthrough in quantitatively constraining bromine chemistry in the polar atmosphere, where this chemistry connects the rapidly changing surface to pollutant fate. Article in Journal/Newspaper Arctic OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) Arctic Proceedings of the National Academy of Sciences 116 29 14479 14484 |
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Open Polar |
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OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) |
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ftncar |
language |
English |
description |
Bromine atoms play a central role in atmospheric reactive halogen chemistry, depleting ozone and elemental mercury, thereby enhancing deposition of toxic mercury, particularly in the Arctic near-surface troposphere. However, direct bromine atom measurements have been missing to date, due to the lack of analytical capability with sufficient sensitivity for ambient measurements. Here we present direct atmospheric bromine atom measurements, conducted in the springtime Arctic. Measured bromine atom levels reached 14 parts per trillion (ppt, pmol mol(-1); 4.2 x 10(8) atoms per cm(-3)) and were up to 3-10 times higher than estimates using previous indirect measurements not considering the critical role of molecular bromine. Observed ozone and elemental mercury depletion rates are quantitatively explained by the measured bromine atoms, providing field validation of highly uncertain mercury chemistry. Following complete ozone depletion, elevated bromine concentrations are sustained by photochemical snowpack emissions of molecular bromine and nitrogen oxides, resulting in continued atmospheric mercury depletion. This study provides a breakthrough in quantitatively constraining bromine chemistry in the polar atmosphere, where this chemistry connects the rapidly changing surface to pollutant fate. |
author2 |
Wang, Siyuan (author) McNamara, Stephen M. (author) Moore, Christopher W. (author) Obrist, Daniel (author) Steffen, Alexandra (author) Shepson, Paul B. (author) Staebler, Ralf M. (author) Raso, Angela R. W. (author) Pratt, Kerri A. (author) |
format |
Article in Journal/Newspaper |
title |
Direct detection of atmospheric atomic bromine leading to mercury and ozone depletion |
spellingShingle |
Direct detection of atmospheric atomic bromine leading to mercury and ozone depletion |
title_short |
Direct detection of atmospheric atomic bromine leading to mercury and ozone depletion |
title_full |
Direct detection of atmospheric atomic bromine leading to mercury and ozone depletion |
title_fullStr |
Direct detection of atmospheric atomic bromine leading to mercury and ozone depletion |
title_full_unstemmed |
Direct detection of atmospheric atomic bromine leading to mercury and ozone depletion |
title_sort |
direct detection of atmospheric atomic bromine leading to mercury and ozone depletion |
publishDate |
2019 |
url |
https://doi.org/10.1073/pnas.1900613116 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic |
genre_facet |
Arctic |
op_relation |
Proceedings of the National Academy of Sciences--Proc Natl Acad Sci USA--0027-8424--1091-6490 articles:22666 ark:/85065/d7m90csp doi:10.1073/pnas.1900613116 |
op_rights |
Copyright 2019 Author(s). Published under license by the National Academy of Sciences. |
op_doi |
https://doi.org/10.1073/pnas.1900613116 |
container_title |
Proceedings of the National Academy of Sciences |
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116 |
container_issue |
29 |
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14479 |
op_container_end_page |
14484 |
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1776198409649127424 |