Daniel Lecoanet - Testing Parameterizations of Convective Overshoot

Event type: 
Seminar
Date: 
23 January 2019
Time: 
2.00 - 3.00pm
Location: 

Climate Change Research Centre, Seminar Room, Mathews Building 4th floor, UNSW, Sydney

Presenter: 
Dr. Daniel Lecoanet
University of California Berkeley, United States
Host: 
Climate Change Research Centre

There are many natural systems with convectively unstable fluid adjacent to stably stratified fluid: the Earth's atmosphere and ocean, as well as most stars, and perhaps even the Earth's liquid core. The convective motions penetrating into the stable region can enhance mixing, leading to changes in transport within the stable region. In this talk, I will present convective overshoot simulations, in which I quantitatively measure the extra mixing due to overshooting motions. I parameterize the extra mixing as a spatially-dependent turbulent diffusivity. Finally, I will test the parameterization and interpret the results.

 

Brief Biography: Daniel is a member of the Univerisity of California, Berkeley Physics department. Daniel works primarily on Astrophysical and Geophysical Fluid Dynamics in subjects including atmospheric convection, internal waves and turbulence. He is also a core developer for Dedalus, a flexible, open-source framework for spectrally solving differential equations.