对流模型在昆明地区降水演变规律中的应用

Application of Convection Model to Evolution Law of Kunming Precipitation

从描述局地降水距平率系统的对流方程和实际气象观测资料出发, 导出并反演了描述昆明局地降水距平率系统的非线性振荡方程。根据非线性振荡理论和昆明地区的非线性振荡方程研究了昆明地区降水距平率系统演变的非线性特征及其演变规律。结果表明: 昆明局地降水距平率系统为一正阻尼的弱非线性振荡系统, 其演变的固有周期为6.5 旬, 在不受外力强迫作用下, 将逐渐趋向于一稳定结点a1(0, 0); 在存在外力强迫作用下, 定性分析表明, 昆明局地降水距平率系统在其演变过程中将随外源强迫的振荡而发生振荡。

Applying convection equation describing local precipitation anomaly system and real-time meteorological observatory data, the nonlinear oscillation equation describing Kunming precipitation anomaly system was derived and retrieved. According to the nonlinear oscillation theory and the obtained equation, the nonlinear characteristics and evolution law of Kunming precipitation anomaly system were studied.Theresults show thatKunming precipitation anomaly systemis a positive damping system with weak nonlinear oscillation. Its natural period is 65 days. Without the exernal forcing, it will go to a stable point %a-1%(0, 0). With the exernal forcing, it will oscillates with the exernal force oscillation.