Atmospheric Circulation Regimes in a Nonlinear Quasi-Geostrophic Model

Figure 10

(Left) estimated probability density in the space spanned by the first two PCs of the 833 hPa geopotential height field. Contour interval is 0.02; zero contour omitted. The thick lines enclose areas with significantly higher probability than what to be expected in the case of adapted red noise process (at the 95% significance level) and thus mark the circulation regimes. The regimes are denoted as indicated in the text. (Right) as left column, but for the layer-averaged NCEP-NCAR reanalysis data with significance at the 85% level.