Improved understanding of polar ozone chemistry and the future of the Antarctic ozone hole
Coupled chemistry-climate models (CCMs) are currently the most appropriate tools for projecting the evolution of the ozone layer through the 21st century and its impact on climate. However, numerous sources of uncertainties in CCM projections of the stratospheric ozone layer were revealed in the pas...
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ftfuberlin:oai:refubium.fu-berlin.de:fub188/3280 2023-05-15T14:00:30+02:00 Improved understanding of polar ozone chemistry and the future of the Antarctic ozone hole Verbessertes Verständis der polaren Ozonchemie und die Zukunft des antarktischen Ozonlochs Kremser, Stefanie w Prof Dr Ulrike Langematz Adjunct Prof Dr Greg Bodeker 2011 XV, 188 S. application/pdf https://refubium.fu-berlin.de/handle/fub188/3280 https://doi.org/10.17169/refubium-7480 https://nbn-resolving.org/urn:nbn:de:kobv:188-fudissthesis000000023834-5 eng eng https://refubium.fu-berlin.de/handle/fub188/3280 http://dx.doi.org/10.17169/refubium-7480 urn:nbn:de:kobv:188-fudissthesis000000023834-5 http://www.fu-berlin.de/sites/refubium/rechtliches/Nutzungsbedingungen microwave radiometry optimal estimation kinetic reaction rates ClO dimer cycle polar ozone chemistry ozone hole ddc:550 doc-type:doctoralThesis 2011 ftfuberlin https://doi.org/10.17169/refubium-7480 2022-05-15T20:50:48Z Coupled chemistry-climate models (CCMs) are currently the most appropriate tools for projecting the evolution of the ozone layer through the 21st century and its impact on climate. However, numerous sources of uncertainties in CCM projections of the stratospheric ozone layer were revealed in the past. In this thesis three sources of uncertainty were investigated: (i) uncertainties in the kinetic reaction rates of an important ozone depleting catalytic cycle, (ii) uncertainties resulting from different future greenhouse gas (GHG) emissions, and (iii) uncertainties in the representation of key chemical processes in CCMs. This thesis presents two methods to derived key kinetic reactions rates driving polar ozone depletion from atmospheric measurements, such as ground-based chlorine monoxide (ClO) measurements, thereby focussing on the kinetic reaction rates driving the effectiveness of the ClO dimer cycle during the day. The ClO dimer is one of the most destructive ozone loss processes in polar regions. The derived results are in agreement with previous studies and confirm that a rather higher value of the ratio of kinetic parameters J/kf (where J is the photolysis frequency and kf is the dimer formation rate) than currently recommended is required to explain the atmospheric measurements. The findings of this thesis highlight the need for long-term atmospheric measurements of day and night-time ClO and ClOOCl (referred to as the ClO dimer) and the need to investigate the kinetic reaction rates under stratospheric conditions. The uncertainty in the ozone projections that arises from the uncertainty in future emissions of GHGs has been subject to the second part of this thesis. A semi-empirical model approach which is used to investigate the evolution of stratospheric activated chlorine concentrations and related changes in Antarctic ozone depletion in a changing climate is presented. The sensitivity of the return dates of Antarctic ozone to historic levels (e.g. 1960 or 1980) to GHG emissions scenarios is examined. ... Doctoral or Postdoctoral Thesis Antarc* Antarctic Antarktis* Freie Universität Berlin: Refubium (FU Berlin) Antarctic The Antarctic |
institution |
Open Polar |
collection |
Freie Universität Berlin: Refubium (FU Berlin) |
op_collection_id |
ftfuberlin |
language |
English |
topic |
microwave radiometry optimal estimation kinetic reaction rates ClO dimer cycle polar ozone chemistry ozone hole ddc:550 |
spellingShingle |
microwave radiometry optimal estimation kinetic reaction rates ClO dimer cycle polar ozone chemistry ozone hole ddc:550 Kremser, Stefanie Improved understanding of polar ozone chemistry and the future of the Antarctic ozone hole |
topic_facet |
microwave radiometry optimal estimation kinetic reaction rates ClO dimer cycle polar ozone chemistry ozone hole ddc:550 |
description |
Coupled chemistry-climate models (CCMs) are currently the most appropriate tools for projecting the evolution of the ozone layer through the 21st century and its impact on climate. However, numerous sources of uncertainties in CCM projections of the stratospheric ozone layer were revealed in the past. In this thesis three sources of uncertainty were investigated: (i) uncertainties in the kinetic reaction rates of an important ozone depleting catalytic cycle, (ii) uncertainties resulting from different future greenhouse gas (GHG) emissions, and (iii) uncertainties in the representation of key chemical processes in CCMs. This thesis presents two methods to derived key kinetic reactions rates driving polar ozone depletion from atmospheric measurements, such as ground-based chlorine monoxide (ClO) measurements, thereby focussing on the kinetic reaction rates driving the effectiveness of the ClO dimer cycle during the day. The ClO dimer is one of the most destructive ozone loss processes in polar regions. The derived results are in agreement with previous studies and confirm that a rather higher value of the ratio of kinetic parameters J/kf (where J is the photolysis frequency and kf is the dimer formation rate) than currently recommended is required to explain the atmospheric measurements. The findings of this thesis highlight the need for long-term atmospheric measurements of day and night-time ClO and ClOOCl (referred to as the ClO dimer) and the need to investigate the kinetic reaction rates under stratospheric conditions. The uncertainty in the ozone projections that arises from the uncertainty in future emissions of GHGs has been subject to the second part of this thesis. A semi-empirical model approach which is used to investigate the evolution of stratospheric activated chlorine concentrations and related changes in Antarctic ozone depletion in a changing climate is presented. The sensitivity of the return dates of Antarctic ozone to historic levels (e.g. 1960 or 1980) to GHG emissions scenarios is examined. ... |
author2 |
w Prof Dr Ulrike Langematz Adjunct Prof Dr Greg Bodeker |
format |
Doctoral or Postdoctoral Thesis |
author |
Kremser, Stefanie |
author_facet |
Kremser, Stefanie |
author_sort |
Kremser, Stefanie |
title |
Improved understanding of polar ozone chemistry and the future of the Antarctic ozone hole |
title_short |
Improved understanding of polar ozone chemistry and the future of the Antarctic ozone hole |
title_full |
Improved understanding of polar ozone chemistry and the future of the Antarctic ozone hole |
title_fullStr |
Improved understanding of polar ozone chemistry and the future of the Antarctic ozone hole |
title_full_unstemmed |
Improved understanding of polar ozone chemistry and the future of the Antarctic ozone hole |
title_sort |
improved understanding of polar ozone chemistry and the future of the antarctic ozone hole |
publishDate |
2011 |
url |
https://refubium.fu-berlin.de/handle/fub188/3280 https://doi.org/10.17169/refubium-7480 https://nbn-resolving.org/urn:nbn:de:kobv:188-fudissthesis000000023834-5 |
geographic |
Antarctic The Antarctic |
geographic_facet |
Antarctic The Antarctic |
genre |
Antarc* Antarctic Antarktis* |
genre_facet |
Antarc* Antarctic Antarktis* |
op_relation |
https://refubium.fu-berlin.de/handle/fub188/3280 http://dx.doi.org/10.17169/refubium-7480 urn:nbn:de:kobv:188-fudissthesis000000023834-5 |
op_rights |
http://www.fu-berlin.de/sites/refubium/rechtliches/Nutzungsbedingungen |
op_doi |
https://doi.org/10.17169/refubium-7480 |
_version_ |
1766269673859448832 |