On the effect of doubling of atmospheric CO2 on the stormtracks in the climate of a general circulation model

We have determined the effect of a doubling of the atmospheric CO2 content on the stormtracks in the climate of a general circulation model. Stormtracks are defined as areas with pronounced geopotential height variability in the 2.25-6 day range. A band- pass filter is designed which filters these periods out of the spectrum. For our analysis we have used the doubled CO2 experiment performed by Wilson and Mitchell (1987). Significant decreases (at a 95 % level of confidence) of the band-pass rms field of the transient part of the 500 hPa height occur over the eastern part of the Pacific stormtrack, over the Atlantic stormtrack off the west-coast of North America and south-east of Africa. Significant increases occur in very high latitudes of the Northern Hemisphere.