大尺度大气运动的倍周期分叉和流型的非周期演变

本文提出了一个控制斜压准地转气流运动的八维非线性自治系统。随着非绝热强迫参数的变化,流型的演变显示出倍周期分叉,比值(r2-r1)/(r3-r2)近似等于Feigenbaum普适常数。越过分叉点r∞后,形成具有四片的怪引子,其结构与三维的Lorenz怪引子及Rössler怪引子不同。

PERIOD-DOUBLING BIFURCATIONS OF THE ATMOSPHERIC CIRCULATION AND APERIODIC VARIATIONS OF THE FLOW PATTERNS

An eighth-order set of ordinary differential equations,which governs the dynamics of a quasigeostrophic flow of the baroclinic atmosphere,is used to investigate bifurcational and chaotic forms of the atmospheric circulation. Numerical integrations of the set exhibit period-doubling bifurcations of the flow patterns. It seems that the Feigenbaum relation (rn-rn-1)/(rn+1-rn)= 4.6692 is satisfied approximately. Above a limit point r∞ the solutions are aperiodic and chaotic,and a strange attractor having four inter-linked chaotic fragments appears. A window of period-6 emerges also in the chaotic region.