Bromine-Chlorine Coupling in the Antarctic Ozone Hole
The contribution from the chlorine and bromine species in the formation of the Antarctic ozone hole is evaluated. Since chlorine and bromine compounds are of different industrial origin, it is desirable, from a policy point of view, to be able to attribute chlorine-catalyzed loss of ozone with those...
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ftnasantrs:oai:casi.ntrs.nasa.gov:19970026038 2023-05-15T13:47:44+02:00 Bromine-Chlorine Coupling in the Antarctic Ozone Hole Sze, Nien-Dak Rodriquez, Jose M. Danilin, Michael Y. Ko, Malcolm K. W. Prather, Michael J. Unclassified, Unlimited, Publicly available Jan. 01, 1996 application/pdf http://hdl.handle.net/2060/19970026038 unknown Document ID: 19970026038 Accession ID: 97N25405 http://hdl.handle.net/2060/19970026038 Copyright, Distribution as joint owner in the copyright CASI Environment Pollution NASA-CR-205162 NAS 1.26:205162 Paper-95GL03783 Geophysical Research Letters (ISSN 0094-8534); 23; 2; 153-156 1996 ftnasantrs 2019-08-31T23:06:22Z The contribution from the chlorine and bromine species in the formation of the Antarctic ozone hole is evaluated. Since chlorine and bromine compounds are of different industrial origin, it is desirable, from a policy point of view, to be able to attribute chlorine-catalyzed loss of ozone with those reactions directly involving chlorine species, and likewise for bromine-catalyzed loss. In the stratosphere, however, most of the chemical families are highly coupled, and, for example, changes in the chlorine abundance will alter the partitioninig in other families and thus the rate of ozone loss. This modeling study examines formation of the Antarctic ozone hole for a wide range of bromine concentrations (5 - 25 pptv) and for chlorine concentrations typical of the last two decades (1.5, 2.5 and 3.5 ppbv). We follow the photochemical evolution of a single parcel of air, typical of the inner Antarctic vortex (50 mbar, 70 deg. S, NO(sub y) = 2 ppbv, with Polar Stratospheric Clouds(PSC)) from August 1 to November 1. For all of these ranges of chlorine and bromine loading, we would predict a substantial ozone hole (local depletion greater than 90%) within the de-nitrified, PSC- perturbed vortex. The contributions of the different catalytic cycles responsible for ozone loss are tabulated. The deep minimum in ozone is driven primarily by the chlorine abundance. As bromine levels decrease, the magnitude of the chlorine-catalyzed ozone loss increases to take up the slack. This is because bromine suppresses ClO by accelerating the conversion of ClO an Cl2O2 back to HCI. For this range of conditions, the local relative efficiency of ozone destruction per bromine atom to that per chlorine atom (alpha-factor) ranges from 33 to 55, decreasing with increase of bromine. Other/Unknown Material Antarc* Antarctic NASA Technical Reports Server (NTRS) Antarctic The Antarctic |
institution |
Open Polar |
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NASA Technical Reports Server (NTRS) |
op_collection_id |
ftnasantrs |
language |
unknown |
topic |
Environment Pollution |
spellingShingle |
Environment Pollution Sze, Nien-Dak Rodriquez, Jose M. Danilin, Michael Y. Ko, Malcolm K. W. Prather, Michael J. Bromine-Chlorine Coupling in the Antarctic Ozone Hole |
topic_facet |
Environment Pollution |
description |
The contribution from the chlorine and bromine species in the formation of the Antarctic ozone hole is evaluated. Since chlorine and bromine compounds are of different industrial origin, it is desirable, from a policy point of view, to be able to attribute chlorine-catalyzed loss of ozone with those reactions directly involving chlorine species, and likewise for bromine-catalyzed loss. In the stratosphere, however, most of the chemical families are highly coupled, and, for example, changes in the chlorine abundance will alter the partitioninig in other families and thus the rate of ozone loss. This modeling study examines formation of the Antarctic ozone hole for a wide range of bromine concentrations (5 - 25 pptv) and for chlorine concentrations typical of the last two decades (1.5, 2.5 and 3.5 ppbv). We follow the photochemical evolution of a single parcel of air, typical of the inner Antarctic vortex (50 mbar, 70 deg. S, NO(sub y) = 2 ppbv, with Polar Stratospheric Clouds(PSC)) from August 1 to November 1. For all of these ranges of chlorine and bromine loading, we would predict a substantial ozone hole (local depletion greater than 90%) within the de-nitrified, PSC- perturbed vortex. The contributions of the different catalytic cycles responsible for ozone loss are tabulated. The deep minimum in ozone is driven primarily by the chlorine abundance. As bromine levels decrease, the magnitude of the chlorine-catalyzed ozone loss increases to take up the slack. This is because bromine suppresses ClO by accelerating the conversion of ClO an Cl2O2 back to HCI. For this range of conditions, the local relative efficiency of ozone destruction per bromine atom to that per chlorine atom (alpha-factor) ranges from 33 to 55, decreasing with increase of bromine. |
format |
Other/Unknown Material |
author |
Sze, Nien-Dak Rodriquez, Jose M. Danilin, Michael Y. Ko, Malcolm K. W. Prather, Michael J. |
author_facet |
Sze, Nien-Dak Rodriquez, Jose M. Danilin, Michael Y. Ko, Malcolm K. W. Prather, Michael J. |
author_sort |
Sze, Nien-Dak |
title |
Bromine-Chlorine Coupling in the Antarctic Ozone Hole |
title_short |
Bromine-Chlorine Coupling in the Antarctic Ozone Hole |
title_full |
Bromine-Chlorine Coupling in the Antarctic Ozone Hole |
title_fullStr |
Bromine-Chlorine Coupling in the Antarctic Ozone Hole |
title_full_unstemmed |
Bromine-Chlorine Coupling in the Antarctic Ozone Hole |
title_sort |
bromine-chlorine coupling in the antarctic ozone hole |
publishDate |
1996 |
url |
http://hdl.handle.net/2060/19970026038 |
op_coverage |
Unclassified, Unlimited, Publicly available |
geographic |
Antarctic The Antarctic |
geographic_facet |
Antarctic The Antarctic |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_source |
CASI |
op_relation |
Document ID: 19970026038 Accession ID: 97N25405 http://hdl.handle.net/2060/19970026038 |
op_rights |
Copyright, Distribution as joint owner in the copyright |
_version_ |
1766247784346812416 |