On stochastic stability of regional ocean models with uncertainty in wind forcing - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Nonlinear Processes in Geophysics Année : 2007

On stochastic stability of regional ocean models with uncertainty in wind forcing

L. M. Ivanov
  • Fonction : Auteur
  • PersonId : 852098

Résumé

A shallow-water model was used to understand model error induced by non-Gaussian wind uncertainty. Although the model was simple, it described a generic system with many degrees of freedom randomized by external noise. The study focused on the nontrivial collective behavior of finite-amplitude perturbations on different scales and their influence on model predictability. The error growth strongly depended on the intensity and degree of spatial inhomogeneity of wind perturbations. For moderate but highly inhomogeneous winds, the error grew as a power law. This behavior was a consequence of varying local characteristic exponents and nonlinear interactions between different scales. Coherent growth of perturbations was obtained for different scales at various stages of error evolution. For the nonlinear stage, statistics of prediction error could be approximated by a Weibull distribution. An approach based on the Kullback-Leibler distance (the relative entropy) and probability-weighted moments was developed for identification of Weibull statistics. Bifurcations of the variance, skewness and kurtosis of the irreversible predictability time (a measure of model prediction skill) were detected when the accepted prediction accuracy (tolerance) exceeded some threshold.
Fichier principal
Vignette du fichier
npg-14-655-2007.pdf (946.09 Ko) Télécharger le fichier
Origine : Accord explicite pour ce dépôt
Loading...

Dates et versions

hal-00302920 , version 1 (18-06-2008)

Identifiants

  • HAL Id : hal-00302920 , version 1

Citer

L. M. Ivanov, P. C. Chu. On stochastic stability of regional ocean models with uncertainty in wind forcing. Nonlinear Processes in Geophysics, 2007, 14 (5), pp.655-670. ⟨hal-00302920⟩

Collections

INSU EGU
54 Consultations
60 Téléchargements

Partager

Gmail Facebook X LinkedIn More