Comparative simulation study of effects of eddy-topography interaction in the East/Japan Sea deep circulation

In this study the structure and seasonal variations of deep mean circulation in the East/lapan Sea （E/S） were numerically simulated using a mid-resolution ocean general circulation model with two different parameterizations for the eddy-topography interaction （ETI）. The strong deep mean circulations observed in the EIS are well reproduced when using the ETI parameterizations. The seasonal variability in the EIS deep layer is shown by using ETI parameterization based on the potential vorticity approach, while it is not shown in the statistical dynamical parameterization. The driving mechanism of the strong deep mean currents in the E/S are discussed by investigating the effects of model grids and parameterizations. The deep mean circulation is more closely related to the baroclinic process and potential vorticity than it is to the wind driven circulation.

An alternative visualization pipeline for large-scale data sets by using early visibility test point rendering

The amount of produced data required to be visualized and analyzed has grown year by year,and the traditional approach of using larger computational resources or exploiting task and data parallelism seems to have reached its limit.Therefore,a new paradigm for large-scale data visualization becomes highly desired,and in this paper,we propose a new and optimized visualization pipeline which uses a point rendering-based early visibility testing for reducing the unnecessary rendering in the final stage of the visualization pipeline,and we named this technique“Early Visibility Test Point Rendering”.In a densely populated polygonal mesh scene,where multiple triangles may cover a single pixel,unnecessary and wasteful rendering will occur in the final stage of the traditional visualization pipeline,that is,during the rasterization process.Therefore,we propose an alternative visualization pipeline by introducing the“Early Visibility Test Point Rendering”for selecting only the visible polygonal elements for a given visualization scene.This visibility testing can be executed on the CPU side,and only the visible polygonal elements are needed to be sent to the GPU for an optimized rendering.We could verify the effectiveness of our proposed approach by using synthetic datasets,and also a real-world large-scale simulation result.

Extraction,classification and visualization of 3-dimensional clouds simulated by cloud-resolving atmospheric model

Cloud-resolving atmospheric general circulation models using large-scale supercomputers reproduce realistic behavior of 3-dimensional atmospheric field on a global scale.To understand the simulation result for scientists,conventional visualization methods based on 2-dimensional cloud classification are not enough for understanding individual clouds and their physical characteristics.In this study,we propose a new 3-dimensional extraction and classification method of simulated clouds based on their 3-dimensional shape and physical properties.Our proposed method extracts individual clouds by cloud water and cloud ice,and classifies them into six types by their altitude and upward flow.We applied the method to time-varying atmospheric simulation data,and attempted to visualize atmospheric phenomena on the tropics such as developing cumulonimbus and tropical cyclone.Two case studies clearly visualize the behavior of individual cloud type and clarify that some cloud types have a relationship with rainfall during active weather phenomena.The proposed method has the potential to analyze such phenomena that develop in the vertical direction as well as the horizontal direction.