Examples of nearly degenerate modes (the parenthesis in the title reports the corresponding eigenvalue divided by the largest eigenvalue). These modes are composed of some prominent feature at the boundaries and a (usually) weaker long mode. The structures at the boundaries correspond to sets of pixels that are heavily affected by filtering. For polarization the dominant effect is the ground removal. At the high and low declination ends of the observed area the redundancy of the observations is low and therefore the degeneracy breaking effects discussed in Sect. 4.2 are mild. For temperature, the high order of the polynomial filtering plays a significant role, adding prominent features at the boundaries at intermediate declinations and increasing the complexity of the long modes. We emphasize that the prominent features at the boundaries saturate the color scale.