LOCALIZED FEATURES OF CHAOTIC SYSTEM AND ATMOSPHERIC PREDICTABILITY

The localized features on chaotic attractor in phase space and predictability are investigated in the present study.It will be suggested that the localized features in phase space have to be considered in determining the predictability.The notions of the local instability including the finite-time and local-time instabilities which determine the growth rate of error are introduced,and the calculation methods are discussed in detail.The results from the calculation of the 3-component Lorenz model show that such instability,correspondingly the growth rate of error,varies dramatically as the trajectories evolve on the chaotic attractor.The region in which the growth rate of error is small is localized considerably,and is separable from the region in which the growth rate is large.The local predictability is of important interest.It is also suggested that such localized features may be the main cause for a great deal of case-to-case variability of the predictive skill in the operational forecasts.