Lab Home | Phone | Search
Center for Nonlinear Studies  Center for Nonlinear Studies
 Colloquia Archive 
 Postdoc Seminars Archive 
 Quantum Lunch 
 Quantum Lunch Archive 
 CMS Colloquia 
 Q-Mat Seminars 
 Q-Mat Seminars Archive 
 P/T Colloquia 
 Kac Lectures 
 Kac Fellows 
 Dist. Quant. Lecture 
 Ulam Scholar 
 CNLS Fellowship Application 
 Student Program 
 Past Visitors 
 History of CNLS 
 Maps, Directions 
 CNLS Office 
Tuesday, January 31, 2012
11:00 AM - 12:00 PM
CNLS Conference Room (TA-3, Bldg 1690)


The Impacts of Effective Diffusion on the Vortex Axisymmetrization Process

Stephen R. Guimond
Goddard Space Flight Center, NASA

The dynamics of vortex axisymmetrization from the perspective of thermal perturbations is investigated using an idealized, nonlinear atmospheric model developed at LANL called HIGRAD. Attempts at reproducing the nonlinear modeling results of previous work (which used a different nonlinear model called WRF) revealed a discrepancy with the impacts of purely asymmetric forcing. The current study finds that linear, thermal asymmetries can have an important, largely positive role on the vortex intensification whereas prior work found nearly the opposite. Absolute angular momentum budgets reveal that the likely reason for the differences is the strength of the basic-state secondary circulation. Radial momentum budgets and sensitivity analysis further reveals that differences in effective diffusion between the two nonlinear models are likely the driving force behind these results. The goal of this work is to understand the dynamics of hurricane intensification. Recent measurements from advanced research radars developed at NASA Goddard Space Flight Center will be shown that provide motivation for the hurricane problem.

Host: Balu Nadiga, CCS-2,, 667-9466