学术活动
大气海洋
On the bottom drag and energy dissipation in the ocean
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主讲人: 阮晓舟
地点: 物理学院北539室(腾讯会议ID 292 753 795)
时间: 2020年11月24日,9:00—10:30
主持 联系人: 杨军
主讲人简介: Xiaozhou Ruan received his Ph.D. from the California Institute of Technology in 2019. He is currently a postdoctoral associate at the Massachusetts Institute of Technology focusing on turbulent mixing in the abyssal ocean and its impact on the larger-scale ocean circulation and climate. His research covers a range of different topics, including geophysical fluid dynamics, boundary layer turbulence, Southern Ocean dynamics and autonomous ocean observations.

The closure of the ocean’s kinetic energy (KE) budget remains an outstanding puzzle in modern oceanography. The energy dissipation is believed to occur primarily in the oceanic bottom boundary layer (BBL) where bottom drag converts the KE from mean flows to heat loss through irreversible mixing. However, large discrepancies still exist in various previous estimates. In this talk, I will present an “anatomy” of the structures associated with balanced oceanic flows over sloping topography and discuss how the coupling between stratification and topographic slopes modifies the bottom stress. In the second part of the talk, I will take you even closer to the ocean bottom by re-examining G.I. Taylor’s celebrated bulk formula for estimating the BBL integrated dissipation rate and further provide theoretical predictions on its performance in the real ocean. The results will help inform a better understanding of the BBL dynamics as well as the closure of the KE budget in the ocean.