A scalable semi‐implicit barotropic mode solver for the ocean component of the model for prediction across scales has been implemented as a competitor to an existing explicit‐subcycling scheme to allow faster and more stable simulations while not sacrificing accuracy. The semi‐implicit solver adopts the pipelined preconditioned bi‐conjugate gradient stabilization algorithm as an iterative solver in conjunction with the restricted additive Schwarz preconditioner that accelerates the convergence rate of the iterative solver. The preconditioner is constructed from a linearized barotropic system that also reorders the system for optimal performance, while the semi‐implicit solver deals with the fully nonlinear barotropic system that requires reassembly of the coefficient matrix for every time step. Several numerical experiments, from simple one‐dimensional tests to three‐dimensional real‐world tests, demonstrate that the semi‐implicit solver has almost the same accuracy and better parallel scalability compared with the existing scheme while allowing faster and more stable simulations. The semi‐implicit solver accelerates the barotropic mode up to 2.9 times faster than the existing scheme on 16,320 processors, leading to an overall runtime speedup of 1.9.

中文翻译：

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适用于MPAS-Ocean的可扩展半隐性正压模式求解器

可扩展的半隐性正模模式求解器可用于模型的海洋分量，以进行跨尺度的预测，它是现有显式子循环方案的竞争者，可在不牺牲精度的情况下实现更快，更稳定的仿真。半隐式求解器采用流水线预处理的双共轭梯度稳定算法作为迭代求解器，并结合受限的加性Schwarz预处理器来加快迭代求解器的收敛速度。预处理器由线性化正压系统构成，该系统还会对系统进行重新排序以获得最佳性能，而半隐式求解器则处理需要在每个时间步重新组装系数矩阵的完全非线性正压系统。几个数值实验 从简单的一维测试到三维真实世界测试，表明半隐式求解器与现有方案相比具有几乎相同的精度和更好的并行可伸缩性，同时允许更快，更稳定的仿真。半隐式求解器可在16320个处理器上将正压模式加速到比现有方案快2.9倍，从而使整体运行时加速1.9。