摘要
In this paper, a new theory of blocking formation was proposed. The nonlinear Schrdinger equation satisfied by nonlear barotropic Rossby waves for the weak shear zonal flow was obtained by using the WKB method. It was pointed out that when the Rossby wavenumbers sarisfied the relation: k/3【m^2【4k^2 (where k and m are the zonal and meridional wavenumbers respectively), the periodic Rossby wave in the atmosphere might produce the modulational instability and form the envelope Rossby solitary wave. Furthermore, the stream function field of the envelope Rossby solitary wave was calculated, and the structure derived here was similar to the dipole blocking in the atmosphere. On the other hand, we also pointed out that the dipole blocking might be caused through the Rossby wave modulational instability, moreover, the dipole blocking could persist for 25 days and disappear through energy dispersion of Rossby waves.
In this paper, a new theory of blocking formation was proposed. The nonlinear Schrdinger equation satisfied by nonlear barotropic Rossby waves for the weak shear zonal flow was obtained by using the WKB method. It was pointed out that when the Rossby wavenumbers sarisfied the relation: k/3<m^2<4k^2 (where k and m are the zonal and meridional wavenumbers respectively), the periodic Rossby wave in the atmosphere might produce the modulational instability and form the envelope Rossby solitary wave. Furthermore, the stream function field of the envelope Rossby solitary wave was calculated, and the structure derived here was similar to the dipole blocking in the atmosphere. On the other hand, we also pointed out that the dipole blocking might be caused through the Rossby wave modulational instability, moreover, the dipole blocking could persist for 25 days and disappear through energy dispersion of Rossby waves.
