*主办单位：数学科学学院
*举办形式：线上
*时间：2021年3月19日周五20:00-21:00
*地点：腾讯会议ID：431 397 045 链接：https://meeting.tencent.com/s/DZSt525IPNVg
*主讲人：陈青山 副教授 （美国克莱姆森大学Clemson University）
*主持人：袁海荣 教授

*报告内容简介：
Many critical applications, such as extreme weather forecast, rely on accurate simulations of the large-scale geophysical flows, namely the ocean and atmosphere. These flows evolve on spatial scales ranging from meters to thousands of kilometers, and on temporal scales ranging from seconds to decades. These scales interact with each other in a highly nonlinear fashion, making it extremely challenging to reliably and accurately capture the long-term dynamics of these flows on numerical models. Unstructured meshes have been gaining popularity in recent years on geophysical models, thanks to its being almost free of polar singularities, and remaining highly scalable even at eddy resolving resolutions. However, to unleash the full potential of these meshes, new schemes are needed. This talk starts with a brief introduction to large-scale geophysical flows. Then a new scheme is introduced, based on the vorticity and divergence variables, and the Hamiltonian approach. The scheme operates on unstructured meshes over a global or bounded domain, conserves both energy and enstrophy, and possesses the optimal dispersive wave relations, which is crucial for the maintenance of the geostrophic balance within the flow. A key idea behind the derivation is the correspondence between the symmetries of the Hamiltonian system and the conservation of key quantities of the physical system (Noether’s theorem). results from a suite of test cases will be presented to demonstrate the superior advantages as well as the limitations of the new scheme.

*主讲人简介：
陈青山，2009年获得美国印第安纳大学应用数学博士学位，长期从事大尺度地球物理流体的分析和计算。现任美国克莱姆森大学（Clemson University)副教授。