On the multiple equilibrium of the development of tropical cyclone in nonlinear CISK model

By using non-static atmosphere equations including basic current, heating force and friction, we discuss the bal-ance amplitude of vertical motion in the conditions of constant heating force, linear and non-linear interaction be-tween large-scale ascending motion and diabatic heating force. In the non-linear condition, the multiple equilibrium feature of the tropical cyclone development is discussed and the reason of the sudden varying of tropical cyclone intensity is studied preliminarily.