The Downward Influence of Ozone Depletion in the Arctic Lower Stratosphere
Severe ozone depletion in the polar lower stratosphere has been linked to significant changes in tropospheric circulation patterns in the both hemispheres. Observed Southern Hemisphere circulation changes are easily reproduced in climate models and may be achieved by either increasing ozone depletin...
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ftunivcam:oai:www.repository.cam.ac.uk:1810/271796 2023-07-30T04:01:25+02:00 The Downward Influence of Ozone Depletion in the Arctic Lower Stratosphere Rae, Cameron Davies 2018-02-07T15:46:36Z application/pdf https://doi.org/10.17863/CAM.18790 https://www.repository.cam.ac.uk/handle/1810/271796 en eng Robinson College Chemistry Department University of Cambridge doi:10.17863/CAM.18790 https://www.repository.cam.ac.uk/handle/1810/271796 All Rights Reserved https://www.rioxx.net/licenses/all-rights-reserved/ Atmospheric Dynamics Stratosphere-Troposphere Coupling Stratospheric Ozone Thesis Doctoral Doctor of Philosophy (PhD) PhD in Chemistry 2018 ftunivcam https://doi.org/10.17863/CAM.18790 2023-07-10T21:29:55Z Severe ozone depletion in the polar lower stratosphere has been linked to significant changes in tropospheric circulation patterns in the both hemispheres. Observed Southern Hemisphere circulation changes are easily reproduced in climate models and may be achieved by either increasing ozone depleting substances in a chemistry-climate model(CCM) or by imposing observed ozone losses as a zonally-symmetric perturbation in a prescribed-ozone global circulation model (GCM). In the Northern Hemisphere however, only the CCM method produces a circulation response in agreement with analysis of observations, while the GCM method is unable to produce any significant tropospheric circulation changes from imposing observed zonal-mean Arctic ozone losses. Confidence in a mechanistic link between Arctic stratospheric ozone change and changes in tropospheric circulation is greatly increased if the change can be reproduced using a GCM in addition to being reproducible in a CCM. This thesis demonstrates that by allowing ozone to vary along longitude, and by imposing ozone depletion during a realistic timeframe, the GCM method can produce circulation changes compatible with both the CCM method and observations. An equivalent-latitude coordinate allows the prescribed ozone field, and imposed ozone losses, to follow the polar vortex as it is systematically disturbed or displaced off the pole throughout the winter, producing a realistic circulation response in the troposphere in contrast to when ozone and its imposed losses are zonally-symmetric. Timing the imposed ozone depletion with the breakup of the polar vortex reveals that the appearance of the circulation response is very sensitive to the relative timing of these events and to the pre-existing dynamical state of the polar vortex. These results demonstrate that prescribing ozone as a zonally symmetric climatology within a GCM, as has been recent practice in the literature, is only representative of the Southern Hemisphere and is inappropriate for accurately representing ... Doctoral or Postdoctoral Thesis Arctic Apollo - University of Cambridge Repository Arctic |
institution |
Open Polar |
collection |
Apollo - University of Cambridge Repository |
op_collection_id |
ftunivcam |
language |
English |
topic |
Atmospheric Dynamics Stratosphere-Troposphere Coupling Stratospheric Ozone |
spellingShingle |
Atmospheric Dynamics Stratosphere-Troposphere Coupling Stratospheric Ozone Rae, Cameron Davies The Downward Influence of Ozone Depletion in the Arctic Lower Stratosphere |
topic_facet |
Atmospheric Dynamics Stratosphere-Troposphere Coupling Stratospheric Ozone |
description |
Severe ozone depletion in the polar lower stratosphere has been linked to significant changes in tropospheric circulation patterns in the both hemispheres. Observed Southern Hemisphere circulation changes are easily reproduced in climate models and may be achieved by either increasing ozone depleting substances in a chemistry-climate model(CCM) or by imposing observed ozone losses as a zonally-symmetric perturbation in a prescribed-ozone global circulation model (GCM). In the Northern Hemisphere however, only the CCM method produces a circulation response in agreement with analysis of observations, while the GCM method is unable to produce any significant tropospheric circulation changes from imposing observed zonal-mean Arctic ozone losses. Confidence in a mechanistic link between Arctic stratospheric ozone change and changes in tropospheric circulation is greatly increased if the change can be reproduced using a GCM in addition to being reproducible in a CCM. This thesis demonstrates that by allowing ozone to vary along longitude, and by imposing ozone depletion during a realistic timeframe, the GCM method can produce circulation changes compatible with both the CCM method and observations. An equivalent-latitude coordinate allows the prescribed ozone field, and imposed ozone losses, to follow the polar vortex as it is systematically disturbed or displaced off the pole throughout the winter, producing a realistic circulation response in the troposphere in contrast to when ozone and its imposed losses are zonally-symmetric. Timing the imposed ozone depletion with the breakup of the polar vortex reveals that the appearance of the circulation response is very sensitive to the relative timing of these events and to the pre-existing dynamical state of the polar vortex. These results demonstrate that prescribing ozone as a zonally symmetric climatology within a GCM, as has been recent practice in the literature, is only representative of the Southern Hemisphere and is inappropriate for accurately representing ... |
format |
Doctoral or Postdoctoral Thesis |
author |
Rae, Cameron Davies |
author_facet |
Rae, Cameron Davies |
author_sort |
Rae, Cameron Davies |
title |
The Downward Influence of Ozone Depletion in the Arctic Lower Stratosphere |
title_short |
The Downward Influence of Ozone Depletion in the Arctic Lower Stratosphere |
title_full |
The Downward Influence of Ozone Depletion in the Arctic Lower Stratosphere |
title_fullStr |
The Downward Influence of Ozone Depletion in the Arctic Lower Stratosphere |
title_full_unstemmed |
The Downward Influence of Ozone Depletion in the Arctic Lower Stratosphere |
title_sort |
downward influence of ozone depletion in the arctic lower stratosphere |
publisher |
Robinson College |
publishDate |
2018 |
url |
https://doi.org/10.17863/CAM.18790 https://www.repository.cam.ac.uk/handle/1810/271796 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic |
genre_facet |
Arctic |
op_relation |
doi:10.17863/CAM.18790 https://www.repository.cam.ac.uk/handle/1810/271796 |
op_rights |
All Rights Reserved https://www.rioxx.net/licenses/all-rights-reserved/ |
op_doi |
https://doi.org/10.17863/CAM.18790 |
_version_ |
1772812162125791232 |