摘要
本文从系统作整体移动的角度出发,针对具有闭合等高线的系统尤其是低值系统,利用坐标变换并结合大气动力学方程组,导出了控制系统移速的方程,并由此讨论了直接影响台风移速的动力原因。指出了影响系统移速的九大因素:(1)系统内的体积平均的风速的改变;(2)系统的体积膨胀与收缩;(3)系统形状的改变;(4)体积平均的动量通量散度;(5)地转参数的作用;(6)环境压力场;(7)系统强度的变化;(8)地形的阻挡作用;(9)摩擦作用。并指出,若不考虑β效应,系统的涡、散场变化与系统移速无关。
If we take a systen as a whole and combine coordinate transformation with the atmospheric dynamic equations, we can get an equation from which we can discuss the dynamical factors which control the movement of a system with close isohypse especially the lows like typhoons.
In this paper, based on the mentioned above, we pointed out that there are 9 factors can influence the speed and acceleration of a system: (i) the change of wind speed averaged by the volume of system; (ii) the expansion or shriking of the system; (iii) the function of Coriolis parameter; (iv) the volume averaged divergence of momentum flux; (v) the change of the system's shape; (vi) the environment pressure field; (vii) the change of system's intensity; (viii) the function of topography; (ix) the function of friction.
In this paper, we also pointed out that if we do not consider the β effect, we will be unable to understand the influence of the change of divergence and vortici-ty field of a system to the moving speed of the system from vorticity and divergence equations.
出处
《气象科学》
CSCD
北大核心
1991年第3期252-261,共10页
Journal of the Meteorological Sciences
