FlowSieve: A Coarse-Graining Utility for Geophysical Flows on the Sphere.

Ocean and atmosphere dynamics span an incredibly wide range of spatial and temporal scales, with spatial scales ranging from the sub-millimetre viscous scales all the way up to planetary scales at tens of thousands of kilometres.Because of the strong non-linear nature of oceanic and atmospheric flows, not only do the behaviour and characteristics change significantly with scale, but important energetic interactions exist between different scales.As a result, an important step in understanding and predicting the behaviour of such complex flow systems is being able to disentangle the complex interactions across this wide range of scales.Coarse-graining is a physically-motivated and mathematically-rigorous technique for partitioning spatial flows as a function of a specified partitioning scale, allowing for a consistent and comprehensive scale-by-scale analysis.