A Multimodel Assessment of Future Projections of North Atlantic and European Extratropical Cyclones in the CMIP5 Climate Models

• Published in: Journal of climate Vol. 26; no. 16; pp. 5846 - 5862
• Main Authors: Zappa, Giuseppe, Shaffrey, Len C., Hodges, Kevin I., Sansom, Phil G., Stephenson, David B.
• Format: Journal Article
• Language: English
• Published: Boston, MA American Meteorological Society 01.08.2013
• Subjects: Algorithms; Atmospheric models; Central Europe; Climate change; Climate models; Climatic zones; Climatology. Bioclimatology. Climate change; Cyclones; Earth, ocean, space; Emission; Emissions; Exact sciences and technology; External geophysics; Extratropical cyclones; Hydrology; Intercomparison; Mathematical models; Meteorology; Modeling; Precipitation; Projection; Rainfall intensity; Reduction; Simulation; Storm tracks; Storms; Storms, hurricanes, tornadoes, thunderstorms; Strong winds; Studies; Tracking; Tropical cyclones; Uncertainty; Wind; Wind speed; Wind velocity; Winds; Atlantic Ocean; Europe; North Atlantic; ANE, Norway; AN, North Atlantic; MED; ANE, Europe; Multimodel; Coupled model; Extratropical cyclone; General circulation models; Severe weather; global change; climate warming; Climate models; digital simulation; climate change; Cyclogenesis
• ISSN: 0894-8755; 1520-0442
• DOI: 10.1175/jcli-d-12-00573.1

The response of North Atlantic and European extratropical cyclones to climate change is investigated in the climate models participating in phase 5 of the Coupled Model Intercomparison Project (CMIP5). In contrast to previous multimodel studies, a feature-tracking algorithm is here applied to separately quantify the responses in the number, the wind intensity, and the precipitation intensity of extratropical cyclones. Moreover, a statistical framework is employed to formally assess the uncertainties in the multimodel projections. Under the midrange representative concentration pathway (RCP4.5) emission scenario, the December–February (DJF) response is characterized by a tripolar pattern over Europe, with an increase in the number of cyclones in central Europe and a decreased number in the Norwegian and Mediterranean Seas. The June–August (JJA) response is characterized by a reduction in the number of North Atlantic cyclones along the southern flank of the storm track. The total number of cyclones decreases in both DJF (−4%) and JJA (−2%). Classifying cyclones according to their intensity indicates a slight basinwide reduction in the number of cyclones associated with strong winds, but an increase in those associated with strong precipitation. However, in DJF, a slight increase in the number and intensity of cyclones associated with strong wind speeds is found over the United Kingdom and central Europe. The results are confirmed under the high-emission RCP8.5 scenario, where the signals tend to be larger. The sources of uncertainty in these projections are discussed.