Mesoscopic dynamics of chaos in chemical Lorenz model

The mesoscopic dynamics of the chemical Lorenz system has been examined wit hin the framework of master equation description by means of ensemble stoch astic simulations. The time evolution of the bin frequency, which approxima tes the probability of the master equation, has been checked in dynamic reg imes of fixed points, limit cycles and chaos. The variances and covariances between different species are also calculated and compared. Results presen ted suggest a picture of mesoscopic dynamics beyond the usual deterministic description.