Atmosphere Ocean Science Student Seminar

Moist Rayleigh-Benard Convection in a rotating frame

Speaker: Mu-Hua Chien, PhD Student, Courant Institute

Location: Warren Weaver Hall 1314

Date: Friday, October 5, 2018, 3:45 p.m.

Synopsis:

We investigate the behavior of moist Rayleigh-Benard convection in the presence of rotation using a Boussinesq model with simplified thermodynamics for condensation of water vapor. We consider the effects of rotation to the idealized configuration that is accessible to high-resolution three-dimensional direct numerical simulations without the small-scale parameterizations of the turbulence for extended layers. Our new implementation applies the AMR software for incompressible flow based on high-order approximate projection method and non-oscillatory finite-Volume scheme. In this report, we verify that our new implementation is capable of resolving the Ekman layer in the geophysical fluid, and then apply this implementation to examine dry convection in the rotating frame.

Next, we investigate moist convection in the rotating frame in the conditionally unstable environment that is stably stratified for unsaturated air but is unstable for cloudy air. We find that the transition is sensitive to rotation effect and both the initial and boundary condition with the fixed aspect ratio of the convective domain. In contrast to non-rotating cases, the pulsating convection turns to the steady convection with the small aspect ratio. Thus, the steady convection produces more vertical transport of momentum and more liquid content from the lower boundary. We also find that the energy transport of conditionally unstable moist convection depends on Ekman transport from the lower boundary.