Using FlowVis techniques to study ocean flows

This paper presents an application of two methods - a new pseudo-LIC method and a novel streamline placement method - for improving the performance of ocean flow visualization over current methods. Instead of directly texture mapping streamlines as previous methods, the new pseudo-LIC method varies the thickness of a streamline according to its distance from its neighbors before mapping a periodic intensity onto the streamline. This method produces LIC-like image with better contrast and finer delineation. With the novel streamline placement method, topology-aware and evenly-spaced streamline placement, intuitive flow characteristics are presented with visually pleasing streamlines. First, singularities and separatrices are extracted to decompose the flow field into topological regions. Then, a preferred seeding path is selected in each region. The uniform sample points on this path are used as seeds to generate streamlines. We applied these two methods to Navy Coastal Ocean Model (NCOM) data. The resulting visualizations demonstrate the effectiveness of these two methods.