Multiplicative noise in atmospheric dynamics: Modeling and observationsPhilip Sura
Scripps Institute of Oceanography
The role of multiplicative noise in atmospheric models and meteorological data analysis is discussed.
On the one hand the concepts of multiplicative stochastic perturbations and noise-induced transitions are applied to a quasi-geostrophic beta-plane model of barotropic flow over topography. The stochastic representation of the damping term leads to a multiplicative stochastic forcing. It is found that the qualitative behavior of the system is a function of the multiplicative noise level. It is suggested that the statistics of the unresolved physical processes could be an important factor to understand the behavior of mid-latitude large-scale atmospheric dynamics.
On the other hand it is shown that a proper stochastic description of synoptic midlatitude sea surface winds requires a multiplicative noise component. For that purpose a general method is used to estimate the drift and diffusion coefficients of a continuous stationary Markovian system. The results indicate that multiplicative noise terms may be necessary in order to fit stochastic models to reality or more complex models.
25 Feb, 2002 (Note: special day)
2 PM/ DSRC 1D 403
(Coffee at 1:50 PM)