Fig. 7: Potential (grey contours) and associated drift (arrows) used in Eq. (1) for the generation of the first three components of the stochastic twins.
From: Disentangling density and geometry in weather regime dimensions using stochastic twins

For each regime, the short names are placed at the regime means. The colored ellipses correspond to isoprobability equal to one-half of the peak probability in the regime centers, as given by each regime’s Gaussian distribution according to the best fit from ERA5 z500 anomalies. NAO: North Atlantic Oscillation. AR: Atlantic Ridge. SB: Scandinavian Blocking.