By author > Blundell Jeffrey

Breeding vectors (Toth and Kalnay, 1991a, 1993) provide a relatively simple method for generation of perturbation growth that approximates the singular modes of the system, all without the need for a tangent linear model. This method requires a small, random perturbation to initial conditions to generate a response over a typical eddy-growth timescale, and for this response to be normalised to small amplitude and reinserted as a perturbation, then the process is repeated. We calculate breeding vectors for the Quasi-Geostrophic Coupled Model (Q-GCM), configured with a periodic channel atmosphere and an ocean basin with a double-gyre circulation. Both atmosphere and ocean are eddy-resolving. We compare breeding vector perturbations with crude, pointwise perturbations and examine the relative rates of ensemble divergence and the relationship of the evolving perturbations with physical modes of the system.