Implementing Fast Modal Filtering of SCALE-DG
Xuanzhengbo Ren, Yuta Kawai, Hirofumi Tomita, Seiya Nishizawa, Takahiro Katagiri, Masatoshi Kawai, Tetsuya Hoshino, Toru Nagai · 2024
For future high-resolution atmospheric simulations, a dynamical core using the discontinuous Galerkin Method (DGM), called SCALE-DG [1], is being developed as an option for high-order fluid schemes in the SCALE library [2]. Compared to the traditional Finite Element Method (FEM), the DGM allows for discontinuities across element boundaries. When evaluating a first-order derivative operator, we use the values at nodes of own element and at common boundaries of neighbor elements. This feature allows most computations to be performed independently for each element. Thus, we can take full advantage of data locality. Additionally, the DGM can achieve high-order accuracy by choosing high-order polynomial basis functions within each element. Therefore, DGM is suitable for high-resolution atmospheric simulations with high-order numerical accuracy, and we expect the computational performance to be highly desirable on modern computer architectures.