Persistent Anomalies, Blocking and Predictability

The rotating annulus experiments presented in the last chapter reproduce some important qualitative features of the atmosphere’s highly complex general circulation. Sequences of daily weather charts show large-scale wave-like patterns retrogressing with respect to a westerly mean zonal flow. These traveling planetary waves have many similarities with the corresponding Rossby wave regime in a rotating annulus. The atmospheric traveling waves, however, are much less regular than the laboratory waves. They are superimposed, moreover, on standing waves forced by zonal asymmetries of the Earth’s surface, as discussed toward the end of Section 4.4, and in Section 4.6.