Collaborative Research: Towards an Accurate, High-Fidelity Modeling System for Multiphysics and Multiscale Coastal Ocean Flows

随着全球变暖和人类活动在沿海水域的快速扩张，现在迫切需要将我们的建模能力提升到一个直接的、高保真的水平，模拟许多新兴的、真实的、多物理场的、多尺度的沿海海洋流动问题。这些问题的例子包括海底漏油，沿海水域的潮汐能开采等。目前，基本上还没有这种水平的模拟模型。该项目的目标是开发计算方法和前所未有的计算机建模系统，不仅适用于这些问题，而且还将为研究许多其他问题提供新的平台。特别地，地球物理流体动力学模型和全三维流体动力学模型通过域分解和双向耦合集成到一个单一的建模系统中，其中前者捕获中尺度[0 (10)km - O(10,000) km]，背景洋流，后者解决亚中尺度[0 (1)m - O(10) km]，复杂的局部现象。目标将通过三个任务来实现：1)关于求解精度、计算效率和传输条件的方法和算法。2)方法和算法的数值实验，在测试问题中的验证，以及一个展示应用。3)开发健壮、高效的建模系统软件包。教育部分旨在提高学生的意识，特别是那些来自代表性不足的群体，对新的计算问题和解决问题的新方法的必要性，激发他们对数值算法和模型开发的兴趣。这部分的活动包括一系列研讨会、教材编制等。

In correspondence with global warming and fast expansion of human activities in coastal waters, it is now becoming urgently needed to advance our modeling capabilities to a level of direct, high-fidelity simulation of many emerging, real-world, multiphysics, multiscale coastal ocean flow problems. Examples of these problems include oil spill at bottom of oceans, tidal energy extraction in coastal waters, etc. Currently, essentially there is no model at this level of simulation. The objective of this project is to develop computational methods and an unprecedented computer modeling system, which will be not only applicable to such problems but also a new platform to study many other problems.In particular, a geophysical fluid dynamics model and a fully 3D fluid dynamics model are integrated via domain decomposition and two-way coupling into a single modeling system, in which the former captures mesoscale [O(10) km - O(10,000) km], background ocean currents and the latter resolves sub-mesoscale [O(1) m - O(10) km], complicated, local phenomena. The objective will be realized via three tasks: 1) Methods and algorithms with regard to solution accuracy, computational efficiency, and transmission condition. 2) Numerical experiments on the methods and algorithms, their validation in test problems, and a showcase application. 3) Development of a robust, efficient software package of the modeling system. The educational component aims at increasing awareness of students, especially those from underrepresented groups, on new computational problems and necessity for new methods of their solution, stimulating their interest in numerical algorithms and model development. The activities of this component include a series of seminars, teaching material development, etc.