Will Extratropical Storms Intensify in a Warmer Climate?

• DOI: 10.1175/2008jcli2678.1
• Publication Date: 2008-11-11T19:15:17Z
• Authors: Lennart Bengtsson; Kevin I. Hodges; Noel Keenlyside
• Keywords: Extratropical cyclone; Cyclogenesis; Storm track

Abstract Extratropical cyclones and how they may change in a warmer climate have been investigated detail with high-resolution version of the ECHAM5 global model. A spectral resolution T213 (63 km) is used for two 32-yr periods at end twentieth twenty-first centuries integrated Intergovernmental Panel on Climate Change (IPCC) A1B scenario. Extremes pressure, vorticity, wind, precipitation associated are compared lower-resolution simulation. Comparison observations extreme wind speeds indicates that model reproduces realistic values. This study also investigates ability to simulate extratropical by computing composites intense storms contrasting them same from 40-yr ECMWF Re-Analysis (ERA-40). Composites time evolution reproduced great fidelity; particular central surface pressure almost exactly replicated, but maximum speed, higher Spatial show distributions winds, different stages cyclone life cycle compare well those ERA-40, as does vertical structure. For century, changes distribution very similar previous study. There small reduction number no significant extremes vorticity both hemispheres. larger regional agreement studies. The largest total precipitation, where increase seen. Cumulative along tracks increases some 11% per track, or about twice while close globally averaged column water vapor (some 27%). Regionally, even because storm tracks.