Southern Hemisphere Storm Track Response to Recent Stratospheric Ozone and Greenhouse Gas Changes
Abstract
In recent decades, the Southern Hemisphere mid-latitude jet has experienced a pronounced poleward shift during austral summer months. Numerous observational and modeling studies have linked the poleward shift in the jet to Antarctic stratospheric ozone depletion, but the exact relationship between recent climate forcings and the tracks of individual extratropical weather systems has largely been unexplored. In this study, we combine numerical modeling output from the Community Atmospheric Model version 3 with a Lagrangian storm tracking algorithm to robustly identify storm track changes associated with stratospheric ozone depletion and greenhouse gas increases over the late 20th Century. The results demonstrate that stratospheric ozone depletion is linked to significant storm track changes during austral summer: 1) a poleward shift in extratropical storm activity over the Southern Ocean and 2) a substantial reduction in the number of storms affecting New Zealand. Storm track changes associated with late 20th century greenhouse gas increases are more modest and are generally within the range of internal variability in the model.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2012
- Bibcode:
- 2012AGUFM.A11O..07G
- Keywords:
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- 3305 ATMOSPHERIC PROCESSES / Climate change and variability;
- 3362 ATMOSPHERIC PROCESSES / Stratosphere/troposphere interactions