Speaker: Dr. Chen Wang (王辰博士)
Time: 12:10-13:10, 5 January 2024 (Friday) (Beijing time)
Venue: A103,Lijiao Building
Abstract
Zonal flows are mean flows in the east--west direction, which are ubiquitous on planets, and can be formed through ‘zonostrophic instability’: within turbulence or random waves, a weak large-scale zonal flow can grow exponentially to become prominent. In this paper, we study the statistical behaviour of the zonostrophic instability and the effect of magnetic fields. We use a stochastic white noise forcing to drive random waves, and study the growth of a mean flow in this random system. The dispersion relation for the growth rate of the expectation of the mean flow is derived, with simple expressions in limits of strong and weak magnetic diffusivity. Numerical simulation of the stochastic flow is performed to confirm the theory. Results indicate that the magnetic field can significantly increase the randomness of the zonal flow.
About Dr. Wang
王辰博士于2020年在英属哥伦比亚大学获得应用数学博士学位,指导教师为 Neil Balmforth 教授。随后在英国埃克塞特大学从事博士后研究,于2023年9月加入北京师范大学数学研究中心和北师大-港浸大应用数学系。王博士的研究方向包括应用分析方法和流体力学。具体包括地球、天文物理中的流体力学,流动中的波动和稳定性,以及渐进分析方法在其中的应用。