The PI's prior work on an essential problem in geophysical fluid dynamics showed that a randomly turbulent mean flow can self- organize into slowly varying zonal jets with flanking patches of high-frequency smaller scale eddies ("storm tracks") under certain conditions. The principal requirement is that the fluid contain vertical and horizontal shears of flow and temperature differences that combine to provide a particular type of instability often found in real atmospheres and oceans. This realistic behaviour developed, and was maintained, in a model with a highly idealized set of theoretical restrictions. His proposed strategy is to gene- rate a small suite of less restricted, but still highly abstract, models by judicious removal of carefully selected simplifications. These would be chosen to illuminate the specific model properties responsible for producing these realistic features as well as for limiting their degree of verisimilitude when compared with planetary-scale atmospheric and oceanic circulations. Another stated purpose is to test the robustness of the verisimilitude already achieved, and to demonstrate that this degree of realism is not an artifact of the mathematical simplifications imposed in earlier models. Such stepwise building of basic understanding will contribute to future advances in extended-range forecasting and climate modelling.
