Abstract:Under the incompressible condition of fluid, this paper presents a new method of calculating vertical velocity by the continuity equation, which is called z-method. The results show that the relationship between horizontal vorticity and vertical motion can also be obtained by the z-method. In other words, when the horizontal vorticity vector rotates counterclockwise, there is a rising motion, and when the horizontal vorticity vector rotates clockwise, there is a sinking motion. The effectiveness verification shows that the method proposed in this paper has high reliability in the high level, and the reliability is slightly weaker in the lower level than that in the upper level, but not ideal in the middle level. A comparisonis made with the effect of the vertical velocity solved by the p-method, finding that the p-method is slightly better than the z-method.