North-Holland Regular and chaotic behavior in the new Lorenz system

The new Lorenz system of general circulation of the atmosphere, which exhibits an immense variety of bifurcation sequences, is studied by computer simulation. When the external heating varies, periodic and turbulent regions are found. In the periodic regions, period-doubling, period-halving and saddle-node bifurcations are observed. Also, at certain parameter intervals, hyster-esis and coexistence of attractors i reported. The chaotic behavior in the turbulent region is discussed with the aid of Lyapunov analysis and correlation dimension calculations. In recent years, a great deal of interest has been focused on studying the complexity of nonlinear dy-namical systems. Lorenz's classical model of thermal convection in the atmosphere [ l] was the first cha-otic system discovered and has been one of the most extensively investigated. As a modification of this model of turbulence generation, in refs. [2,3] Lor-enz derived a simple but powerful model based on the "general circulation " of the atmosphere. In ref. [ 3], when the external heating F varies and the heat