Interactions of bromine, chlorine, and iodine photochemistry during ozone depletions in Barrow, Alaska
The springtime depletion of tropospheric ozone in the Arctic is known to be caused by active halogen photochemistry resulting from halogen atom precursors emitted from snow, ice, or aerosol surfaces. The role of bromine in driving ozone depletion events (ODEs) has been generally accepted, but much l...
| Main Authors: | , , , , , , , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2015-08-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | http://www.atmos-chem-phys.net/15/9651/2015/acp-15-9651-2015.pdf |
| _version_ | 1818475240877981696 |
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| author | C. R. Thompson P. B. Shepson J. Liao L. G. Huey E. C. Apel C. A. Cantrell F. Flocke J. Orlando A. Fried S. R. Hall R. S. Hornbrook D. J. Knapp R. L. Mauldin III D. D. Montzka B. C. Sive K. Ullmann P. Weibring A. Weinheimer |
| author_facet | C. R. Thompson P. B. Shepson J. Liao L. G. Huey E. C. Apel C. A. Cantrell F. Flocke J. Orlando A. Fried S. R. Hall R. S. Hornbrook D. J. Knapp R. L. Mauldin III D. D. Montzka B. C. Sive K. Ullmann P. Weibring A. Weinheimer |
| author_sort | C. R. Thompson |
| collection | DOAJ |
| description | The springtime depletion of tropospheric ozone in the Arctic is known to be
caused by active halogen photochemistry resulting from halogen atom
precursors emitted from snow, ice, or aerosol surfaces. The role of bromine
in driving ozone depletion events (ODEs) has been generally accepted, but
much less is known about the role of chlorine radicals in ozone depletion
chemistry. While the potential impact of iodine in the High Arctic is more
uncertain, there have been indications of active iodine chemistry through
observed enhancements in filterable iodide, probable detection of
tropospheric IO, and recently, observation of snowpack photochemical
production of I<sub>2</sub>. Despite decades of research, significant uncertainty
remains regarding the chemical mechanisms associated with the
bromine-catalyzed depletion of ozone, as well as the complex interactions
that occur in the polar boundary layer due to halogen chemistry. To
investigate this, we developed a zero-dimensional photochemical model,
constrained with measurements from the 2009 OASIS field campaign in Barrow,
Alaska. We simulated a 7-day period during late March that included a full
ozone depletion event lasting 3 days and subsequent ozone recovery to study
the interactions of halogen radicals under these different conditions. In
addition, the effects of iodine added to our Base Model were investigated.
While bromine atoms were primarily responsible for ODEs, chlorine and iodine
were found to enhance the depletion rates and iodine was found to be more
efficient per atom at depleting ozone than Br. The interaction between
chlorine and bromine is complex, as the presence of chlorine can increase the
recycling and production of Br atoms, while also increasing reactive bromine
sinks under certain conditions. Chlorine chemistry was also found to have
significant impacts on both HO<sub>2</sub> and RO<sub>2</sub>, with organic compounds
serving as the primary reaction partner for Cl atoms. The results of this
work highlight the need for future studies on the production mechanisms of
Br<sub>2</sub> and Cl<sub>2</sub>, as well as on the potential impact of iodine in the
High Arctic. |
| first_indexed | 2024-12-10T09:10:29Z |
| format | Article |
| id | doaj.art-1f7e63333f9941f7be67671b07acef24 |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-12-10T09:10:29Z |
| publishDate | 2015-08-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-1f7e63333f9941f7be67671b07acef242022-12-22T01:55:01ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242015-08-0115169651967910.5194/acp-15-9651-2015Interactions of bromine, chlorine, and iodine photochemistry during ozone depletions in Barrow, AlaskaC. R. Thompson0P. B. Shepson1J. Liao2L. G. Huey3E. C. Apel4C. A. Cantrell5F. Flocke6J. Orlando7A. Fried8S. R. Hall9R. S. Hornbrook10D. J. Knapp11R. L. Mauldin III12D. D. Montzka13B. C. Sive14K. Ullmann15P. Weibring16A. Weinheimer17Department of Chemistry, Purdue University, West Lafayette, Indiana, USADepartment of Chemistry, Purdue University, West Lafayette, Indiana, USASchool of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia, USASchool of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia, USANational Center for Atmospheric Research, Boulder, Colorado, USANational Center for Atmospheric Research, Boulder, Colorado, USANational Center for Atmospheric Research, Boulder, Colorado, USANational Center for Atmospheric Research, Boulder, Colorado, USANational Center for Atmospheric Research, Boulder, Colorado, USANational Center for Atmospheric Research, Boulder, Colorado, USANational Center for Atmospheric Research, Boulder, Colorado, USANational Center for Atmospheric Research, Boulder, Colorado, USANational Center for Atmospheric Research, Boulder, Colorado, USANational Center for Atmospheric Research, Boulder, Colorado, USAInstitute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, New Hampshire, USANational Center for Atmospheric Research, Boulder, Colorado, USANational Center for Atmospheric Research, Boulder, Colorado, USANational Center for Atmospheric Research, Boulder, Colorado, USAThe springtime depletion of tropospheric ozone in the Arctic is known to be caused by active halogen photochemistry resulting from halogen atom precursors emitted from snow, ice, or aerosol surfaces. The role of bromine in driving ozone depletion events (ODEs) has been generally accepted, but much less is known about the role of chlorine radicals in ozone depletion chemistry. While the potential impact of iodine in the High Arctic is more uncertain, there have been indications of active iodine chemistry through observed enhancements in filterable iodide, probable detection of tropospheric IO, and recently, observation of snowpack photochemical production of I<sub>2</sub>. Despite decades of research, significant uncertainty remains regarding the chemical mechanisms associated with the bromine-catalyzed depletion of ozone, as well as the complex interactions that occur in the polar boundary layer due to halogen chemistry. To investigate this, we developed a zero-dimensional photochemical model, constrained with measurements from the 2009 OASIS field campaign in Barrow, Alaska. We simulated a 7-day period during late March that included a full ozone depletion event lasting 3 days and subsequent ozone recovery to study the interactions of halogen radicals under these different conditions. In addition, the effects of iodine added to our Base Model were investigated. While bromine atoms were primarily responsible for ODEs, chlorine and iodine were found to enhance the depletion rates and iodine was found to be more efficient per atom at depleting ozone than Br. The interaction between chlorine and bromine is complex, as the presence of chlorine can increase the recycling and production of Br atoms, while also increasing reactive bromine sinks under certain conditions. Chlorine chemistry was also found to have significant impacts on both HO<sub>2</sub> and RO<sub>2</sub>, with organic compounds serving as the primary reaction partner for Cl atoms. The results of this work highlight the need for future studies on the production mechanisms of Br<sub>2</sub> and Cl<sub>2</sub>, as well as on the potential impact of iodine in the High Arctic.http://www.atmos-chem-phys.net/15/9651/2015/acp-15-9651-2015.pdf |
| spellingShingle | C. R. Thompson P. B. Shepson J. Liao L. G. Huey E. C. Apel C. A. Cantrell F. Flocke J. Orlando A. Fried S. R. Hall R. S. Hornbrook D. J. Knapp R. L. Mauldin III D. D. Montzka B. C. Sive K. Ullmann P. Weibring A. Weinheimer Interactions of bromine, chlorine, and iodine photochemistry during ozone depletions in Barrow, Alaska Atmospheric Chemistry and Physics |
| title | Interactions of bromine, chlorine, and iodine photochemistry during ozone depletions in Barrow, Alaska |
| title_full | Interactions of bromine, chlorine, and iodine photochemistry during ozone depletions in Barrow, Alaska |
| title_fullStr | Interactions of bromine, chlorine, and iodine photochemistry during ozone depletions in Barrow, Alaska |
| title_full_unstemmed | Interactions of bromine, chlorine, and iodine photochemistry during ozone depletions in Barrow, Alaska |
| title_short | Interactions of bromine, chlorine, and iodine photochemistry during ozone depletions in Barrow, Alaska |
| title_sort | interactions of bromine chlorine and iodine photochemistry during ozone depletions in barrow alaska |
| url | http://www.atmos-chem-phys.net/15/9651/2015/acp-15-9651-2015.pdf |
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