Shane D. Ross

Chaotic dynamics in geophysical flows and connections with field experiments

Lagrangian techniques for revealing the most influential transport structures in geophysical flows—including Lagrangian coherent structures (LCSs)—are poised to make an impact on the understanding, and short-term prediction, of material transport, with application to dispersion in the ocean and atmosphere. However, more work is necessary to bridge the gap between powerful theoretical concepts and practical field experiments. Here we discuss some results relevant for real-time analysis and prediction of geophysical transport structures which have arisen from field applications, specifically, spread of plant pathogens or pollen in the atmosphere and search-and-rescue applications in the ocean. We discuss the incorporation of Lagrangian structure into reduced order modeling of geophysical flows and discuss challenges involved in forecasting LCSs, including the effect of spatial averaging and ensemble averaging. We also consider the local approximation of the most influential material surfaces via monitoring of velocity gradients.