Deconstructing the response of high-impact mid-latitude weather systems to climate change
Abstract
Mid-latitude weather and climate are shaped by an interplay between the jet streams, eastward-moving extratropical cyclones and occasional persistent anticyclonic regimes known as blocking. Whilst clearly related, substantial uncertainties remain in climate change projections of each component. In this study relationships between the responses of the jet streams, storms tracks and blocking, and changes in the large-scale temperature structure of the atmosphere are explored through a joint analysis of CMIP5 model simulations and a set of GCM sensitivity experiments. The results suggest that, whilst enhanced upper-tropospheric tropical warming under climate change influences the spatial pattern of the storm tracks, the large spread of projections is more strongly associated with the large spread in lower-tropospheric Arctic warming amongst models. In contrast, both regions of warming act to strengthen the projected decline in blocking, although the impacts of blocking associated with wintertime cold-air outbreaks are substantially reduced by lower-tropospheric Arctic warming.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFM.A12D..01H
- Keywords:
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- 3305 Climate change and variability;
- ATMOSPHERIC PROCESSESDE: 1620 Climate dynamics;
- GLOBAL CHANGEDE: 4313 Extreme events;
- NATURAL HAZARDSDE: 4318 Statistical analysis;
- NATURAL HAZARDS