The steady motion and spiral pattern in typhoon with condensed water

On the basis of Newton's second motion law, the perturbation-condensed water is added to the motion equation in vertical direction, and then the rationality and physical meaning for this addition are discussed. In this paper, the focus is laid on the analysis for characteristics of typhoon, at the same time, the steady three-dimensional stream field and the corresponding pressure and temperature fields are obtained. The three-dimensional velocity fields construct a nonlinear autonomous system in the physical space. It is shown that the center of typhoon is a local minimum pressure with positive vertical vorticity and horizontal divergence in the upper levels. Because there are two saddle-focus points in the autonomous system, there exist the spiral patterns, in which the winds blow spirally in and out of the center in the lower and upper levels in the Northern Hemisphere, which causes the ascending motion near the center and descending motion near the edge, respectively. All these are consistent with the observations. It implies that the typhoons still have the spiral structure characteristics even the condensed water is included.EI05788-7964