Optimized wavelet‐based adaptive mesh refinement algorithm for numerical modeling of three‐dimensional global‐scale atmospheric chemical transport
Optimized wavelet‐based adaptive mesh refinement algorithm for numerical modeling of three‐dimensional global‐scale atmospheric chemical transport
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DOI：
10.1002/qj.3752
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发表时间：
2020-02
影响因子：
8.9
通讯作者：
A. Semakin;Y. Rastigejev
中科院分区：
文献类型：
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作者：
A. Semakin;Y. Rastigejev
与多尺度全球大气化学传输的计算建模相关的大量数值困难对非自适应固定网格的空间分辨率施加了严重的限制。粗糙的空间离散化将大量的数值扩散引入系统，这与强流拉伸相结合，导致大的数值误差。为了解决这个问题，我们开发了一种优化的基于小波的自适应网格细化（OWAMR）方法。OWAMR是一种三维自适应方法，仅在出现小空间结构的区域动态引入细网格。该算法使用了一种新的双参数自适应准则，与基于小波的自适应技术和高阶迎风格式所使用的更传统的单参数网格自适应相比，该准则显着减少了网格点的数量（因子在1.5和2.7之间），这使得人们能够大幅提高平流算子的近似精度。它已被证明，该方法模拟的污染羽流，在全球范围内旅行的动态，产生小于3%的误差。为了达到这样的精度，传统的三维非自适应技术将需要五个数量级以上的计算资源。因此，该方法提供了一个现实的机会，准确地模拟各种最苛刻的多尺度问题在大气化学传输领域，这是很难或不可能模拟现有的计算设施与传统的固定网格技术。
Substantial numerical difficulties associated with the computational modeling of multiscale global atmospheric chemical transport impose severe limitations on the spatial resolution of nonadaptive fixed grids. The crude spatial discretization introduces a large amount of numerical diffusion into the system, which, in combination with strong flow stretching, causes large numerical errors. To resolve this issue, we have developed an optimized wavelet‐based adaptive mesh refinement (OWAMR) method. The OWAMR is a three‐dimensional adaptive method that introduces a fine grid dynamically only in the regions where small spatial structures occur. The algorithm uses a new two‐parameter adaptation criterion that significantly (by factors between 1.5 and 2.7) reduces the number of grid points compared with the more conventional one‐parameter grid adaptation used by wavelet‐based adaptive techniques and high‐order upwind schemes, which enable one to increase the accuracy of approximation of the advection operator substantially. It has been shown that the method simulates the dynamics of a pollution plume that travels on a global scale, producing less than 3% error. To achieve such accuracy, conventional three‐dimensional nonadaptive techniques would require five orders of magnitude more computational resources. Therefore, the method provides a realistic opportunity to model accurately a variety of the most demanding multiscale problems in the area of atmospheric chemical transport, which are difficult or impossible to simulate on existing computational facilities with conventional fixed‐grid techniques.