The mechanism of halogen liberation in the polar troposphere
International audience Sudden depletions of tropospheric ozone during spring were reported from the Arctic and also from Antarctic coastal sites. Field studies showed that those depletion events are caused by reactive halogen species, especially bromine compounds. However the source and seasonal var...
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ftinsu:oai:HAL:hal-00301326v1 2023-11-12T04:04:55+01:00 The mechanism of halogen liberation in the polar troposphere Lehrer, E. Hönninger, G. Platt, U. Institut für Umweltphysik Heidelberg Universität Heidelberg Heidelberg = Heidelberg University 2004-06-28 https://hal.science/hal-00301326 https://hal.science/hal-00301326/document https://hal.science/hal-00301326/file/acpd-4-3607-2004.pdf en eng HAL CCSD European Geosciences Union hal-00301326 https://hal.science/hal-00301326 https://hal.science/hal-00301326/document https://hal.science/hal-00301326/file/acpd-4-3607-2004.pdf info:eu-repo/semantics/OpenAccess ISSN: 1680-7367 EISSN: 1680-7375 Atmospheric Chemistry and Physics Discussions https://hal.science/hal-00301326 Atmospheric Chemistry and Physics Discussions, 2004, 4 (3), pp.3607-3652 [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere info:eu-repo/semantics/article Journal articles 2004 ftinsu 2023-10-25T16:27:04Z International audience Sudden depletions of tropospheric ozone during spring were reported from the Arctic and also from Antarctic coastal sites. Field studies showed that those depletion events are caused by reactive halogen species, especially bromine compounds. However the source and seasonal variation of reactive halogen species is still not completely understood. There are several indications that the halogen mobilisation from the sea ice surface of the polar oceans may be the most important source for the necessary halogens. Here we present a 1-D model study aimed at determining the primary source of reactive halogens. The model includes gas phase and heterogeneous bromine and chlorine chemistry as well as vertical transport between the surface and the top of the boundary layer. The autocatalytic Br release by photochemical processes (bromine explosion) and subsequent rapid bromine catalysed ozone depletion is well reproduced in the model and the major source of reactive bromine appears to be the sea ice surface. The sea salt aerosol alone is not sufficient to yield the high levels of reactive bromine in the gas phase necessary for fast ozone depletion. However, the aerosol efficiently 'recycles' less reactive bromine species (e.g. HBr) and feeds them back into the ozone destruction cycle. Isolation of the boundary layer air from the free troposphere by a strong temperature inversion was found to be critical for boundary layer ozone depletion to happen. The combination of strong surface inversions and presence of sunlight occurs only during polar spring. Article in Journal/Newspaper Antarc* Antarctic Arctic Sea ice Institut national des sciences de l'Univers: HAL-INSU Antarctic Arctic |
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Open Polar |
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Institut national des sciences de l'Univers: HAL-INSU |
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ftinsu |
language |
English |
topic |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere |
spellingShingle |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere Lehrer, E. Hönninger, G. Platt, U. The mechanism of halogen liberation in the polar troposphere |
topic_facet |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere |
description |
International audience Sudden depletions of tropospheric ozone during spring were reported from the Arctic and also from Antarctic coastal sites. Field studies showed that those depletion events are caused by reactive halogen species, especially bromine compounds. However the source and seasonal variation of reactive halogen species is still not completely understood. There are several indications that the halogen mobilisation from the sea ice surface of the polar oceans may be the most important source for the necessary halogens. Here we present a 1-D model study aimed at determining the primary source of reactive halogens. The model includes gas phase and heterogeneous bromine and chlorine chemistry as well as vertical transport between the surface and the top of the boundary layer. The autocatalytic Br release by photochemical processes (bromine explosion) and subsequent rapid bromine catalysed ozone depletion is well reproduced in the model and the major source of reactive bromine appears to be the sea ice surface. The sea salt aerosol alone is not sufficient to yield the high levels of reactive bromine in the gas phase necessary for fast ozone depletion. However, the aerosol efficiently 'recycles' less reactive bromine species (e.g. HBr) and feeds them back into the ozone destruction cycle. Isolation of the boundary layer air from the free troposphere by a strong temperature inversion was found to be critical for boundary layer ozone depletion to happen. The combination of strong surface inversions and presence of sunlight occurs only during polar spring. |
author2 |
Institut für Umweltphysik Heidelberg Universität Heidelberg Heidelberg = Heidelberg University |
format |
Article in Journal/Newspaper |
author |
Lehrer, E. Hönninger, G. Platt, U. |
author_facet |
Lehrer, E. Hönninger, G. Platt, U. |
author_sort |
Lehrer, E. |
title |
The mechanism of halogen liberation in the polar troposphere |
title_short |
The mechanism of halogen liberation in the polar troposphere |
title_full |
The mechanism of halogen liberation in the polar troposphere |
title_fullStr |
The mechanism of halogen liberation in the polar troposphere |
title_full_unstemmed |
The mechanism of halogen liberation in the polar troposphere |
title_sort |
mechanism of halogen liberation in the polar troposphere |
publisher |
HAL CCSD |
publishDate |
2004 |
url |
https://hal.science/hal-00301326 https://hal.science/hal-00301326/document https://hal.science/hal-00301326/file/acpd-4-3607-2004.pdf |
geographic |
Antarctic Arctic |
geographic_facet |
Antarctic Arctic |
genre |
Antarc* Antarctic Arctic Sea ice |
genre_facet |
Antarc* Antarctic Arctic Sea ice |
op_source |
ISSN: 1680-7367 EISSN: 1680-7375 Atmospheric Chemistry and Physics Discussions https://hal.science/hal-00301326 Atmospheric Chemistry and Physics Discussions, 2004, 4 (3), pp.3607-3652 |
op_relation |
hal-00301326 https://hal.science/hal-00301326 https://hal.science/hal-00301326/document https://hal.science/hal-00301326/file/acpd-4-3607-2004.pdf |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1782341808530915328 |