If you're interested in playing with this visualization technique (particle advection in vector fields) outside the context of geospatial applications - I built

If you're interested in playing with this visualization technique (particle advection in vector fields) outside the context of geospatial applications - I built this tool called "Vector Toy" which allows you to visualize any given (2D) vector field this way: http://dandelany.github.io/vector-toy/ http://dandelany.github.io/vector-toy/ - note that the functions on the right side are editable.