Statistical Characteristics of Irreversible Predictability Time in Regional Ocean Models
Abstract
Probabilistic aspects of regional ocean model predictability is analyzed using the probability density function (PDF) of the irreversible predictability time (IPT) (called tau-PDF) computed from an unconstrained ensemble of stochastic perturbations in initial conditions, winds, and open boundary conditions. Two-attractors (a chaotic attractor and a small-amplitude stable limit cycle) are found in the wind-driven circulation. Relationship between attractor's residence time and IPT determines the tau-PDF for the short (up to several weeks) and intermediate (up to two months) predictions. The tau-PDF is usually non-Gaussian but not multi-modal for red-noise perturbations in initial conditions and perturbations in the wind and open boundary conditions. Bifurcation of tau-PDF occurs as the tolerance level varies. Generally, extremely successful predictions (corresponding to the tau-PDF's tail toward large IPT domain) are not outliers and share the same statistics as a whole ensemble of predictions.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 2005
- Accession Number
- ADA479384
Entities
People
- L. M. Ivanov
- Peter Cheng Chu
Organizations
- Naval Postgraduate School