Rossby waves and dipole blocking of barotropic-baroclinic coherent structures in unequal depth two-layer fluids

In this paper, coupled Kadomtsev-Petviashvili (KP) equations describing Rossby waves in barotropic-baroclinic coherent structures are derived from the two-layer quasi-geostrophic vortex equations using multi-scale analysis. The soliton solutions of the coupled KP equations are obtained by applying the elliptic function expansion method. On this basis, the structural distribution and climatic effects of dipole blocking are discussed. The results show that increasing the meridional wave number tilts the symmetric structure of the dipole in the east-west direction, and the dipole structure affects the airflow in the blocked region. In addition, stability conditions for the coupled KP equations are given.