Multiple Scatter Plots-based Multi-Dimensional Transfer Function and its Application to Ocean Data Visualization

Abstract

Abstract. To understand simulation data from the perspective of multivariables is important in numerical simulation study. This study proposes a new multi-dimensional transfer function that enables users to extract and visualize characteristic features with their empirical and intuitive judgment. In the proposed method, data points that represent characteristic features are selected in a couple of 2-dimensional scatter plots. Extracted data in each 2-variable space of multivariate datasets are assigned to different color components such as hue, saturation and/or brightness, respectively, in order to classify and specify the characteristic features. We applied the method to high-resolution ocean simulation data with the advice of oceanographers. As a result of case studies, ocean currents and eddies are intuitively extracted and clearly represented with their physical properties such as current speed, temperature and salinity.

Event detection and visualization of ocean eddies simulated by ocean general circulation model

“…Our technique uses various colors and brightness levels to indicate different phenomena; an approach commonly employed in ocean sciences. 10,29 Basically, warm eddies, cold eddies, streams and currents are colored red, blue, green and yellow, respectively. In addition, specific types of eddies are emphasized by controlling brightness levels as shown in Table 1.…”

“…This is especially true for data sets generated by high-resolution OGCMs, which reproduce so many eddies that it becomes a problem to use traditional visualization methods to address "when, where, and what kind of phenomena have occurred". [7][8][9][10] Envisioning events such as eddy creation, dissipation, amalgamation, and bifurcation in addition to visualizing position information makes it possible to more intuitively understand eddy behavior. To visualize all these, initially, priority lies in detecting eddies and tracking how they change over time.…”