Winter storm track activity overthe Northern Hemisphereandits changes in a greenhouse gas scenario (SRES A1B forcing) arecomputed froman ensembleof 23 single runsfrom sixteen CGCMs. All models reproduce the general structures of the observed climatological stormtrack pattern under present day forcing conditions. Ensemble mean changes due to anthropogenic forcing include an increase of baroclinic wave activity over the eastern North Atlantic, amounting to 5-8% by the end of the 21st century. Enhanced activity is also found over the Asian continent and over the North Pacific near the Aleutian Islands. At high latitudes and over parts the subtropics, activity is reduced. Variations of the individual models around the ensemble average signal are not small, with a median of the pattern correlation near r=0.5. There is, however, no evidence for a link between deviations in present day climatology and deviations with respect to climate change.

Last Updated: 2008-08-21