本文用五分量的低阶截谱,研究了旋转地球上耗散系统在平均温度场强迫下,二维板对称扰动的非线性不稳定性,得出了蝴蝶型突变。对于指定的水平温度梯度值,随静力稳定度的减小,系统平衡态一般经历从静止单稳态向一定环流强度单稳态的突跳,以后又稳定在强环流的双稳态;而且不出现周期和非周期变化现象。当水平温度梯度不存在时,则只要有一定的较弱的垂直涡粘性,系统本身的非线性作用和环境的静力不稳定性,就可导致周期或非周期变化。 In this paper, we study the nonlinear instability of the two-dimensional plate-symmetric perturbation under the action of the average temperature field in the dissipative system on a rotating earth with a five-component low-order cutoff spectrum and obtain the butterfly-type mutation. For a given horizontal temperature gradient, as the static stability decreases, the system equilibrium usually undergoes a monostable sudden jump from stationary monostable to a certain circulation intensity and later stabilizes in a strongly circulated bistable state; and No periodic and non-periodic changes occur. When the horizontal temperature gradient does not exist, periodic or aperiodic changes can occur as long as there is a certain weak vertical vortex viscosity, the nonlinear effect of the system itself and the static instability of the environment.