Dynamical Systems Seminar: Yue-Kin Tsang

Advection-condensation of water vapor in a model of coherent stirring  

Joint talk with Atmospheric and Oceanic Sciences (ATOC)

Yue-Kin Tsang

School of Mathematics, University of Edinburgh

Date and time: 

Thursday, October 23, 2014 - 2:00pm

Location: 

ECCR 257

Abstract: 

Atmospheric water vapor is an essential ingredient of weather and being a potent greenhouse gas, its distribution has a strong impact on climate. The dynamics of atmospheric moisture has previously been studied (Pierrehumbert et al., O’Gorman & Schneider, Sukhatme & Young) using idealized one-dimensional stochastic models in which moisted air parcels are advected by spatially decorrelated random motion and condensation occurs when the specific humidity of a parcel exceeds the local value of a spatially dependent saturation profile. However, coherent sturctures are abundant in the atmosphere. In this work we examine the effect of a coherent flow represented by a single vortex which adds a deterministic component to the random motion of the air parcels. We consider both the initial-value and the steady-state problem of our two-dimensional model and derive the probability distribution of the moisture field. Theoretical predictions are verified by Monte Carlo simulations.