Differences in the non-stationary influence of the North Atlantic Oscillation on European precipitation under different scenarios of greenhouse gas concentrations

The changing spatial patterns of the North Atlantic Oscillation (NAO) dipole and the changing correlations between the NAO and European precipitation were analyzed using the AOGCM CGCM3.1(T63) model provided by the Canadian Centre for Climate Modelling and Analysis (CCCma). Four output scenarios were considered: the IPCC pre-industrial (PI) scenario, the 20th century (20C) scenario, and the B1 and A2 emission scenarios for the 21st century. We detected some differences in the spatial patterns of the NAO-precipitation relationship among the four scenarios. Moreover, there were large differences in the temporal stability of the NAO pressure pattern, and also in the NAO-precipitation relationship among the four scenarios. Under increased greenhouse gas emissions the stability of the NAO-precipitation correlations is enhanced due to the lower variability in the pattern of the NAO dipole.