宁夏各站年降水的非线性特征分析

从观测资料出发,利用非线性振动理论对宁夏年降水气候振动的非线性特征进行了分析和研究,并且利用反演得到的非线性动力学方程对19个站的年降水气候振动进行气候模拟试验,结果表明宁夏大部分地区的年降水气候振动存在弱的非线性振动特征。19个站的年降水气候振动都可看作是一个负阻尼的动力系统,其固有周期的变化范围为1.0～4.1年。年降水气候振动是一个弱的非线性动力系统。这些站点的年降水气候振动是一个类似于具有渐软弹簧特性的非线性动力系统,都存在一个稳定的焦点,但不存在极限环。在降水气候振动中,靠近中北部的地区外源强迫影响作用比南部地区的大。

Nonlinear Dynamic Feature of Annual Precipitation in Every Station of Ningxia

According to the observational data in Ningxia,we analyzed the nonlinear characteristics of the annual precipitation climate vibration by using the theory of non-linear vibration,and retrieved the nonlinear dynamical equations describing the annual precipitation climate oscillation in 19 stations of Ningxia.The results showed that the annual precipitation climate oscillation system of most stations in Ningxia existed weak nonlinear oscillation feature.The annual precipitation climate oscillation system of 19 stations could be seen as a negative damped dynamic system,with the natural period from 1.0 to 4.1 years.The annual precipitation climate oscillation of these stations was a weak nonlinear dynamic system,and it was similar to the gradually soft spring characteristic.All they had stable focus,but no limit cycle.The effect of exogenous force was bigger in the mid-north area than that in the south area.