Dynamics and Variability of Northern Hemisphere Storm Tracks

Florida State University, Tallahassee FL

Investigators

Abstract

Under this award, Dr. Chang will investigate the dynamics of mid-latitude storm tracks and their relationship with the basic state atmospheric flow. His goal is to understand what drives the seasonal and interannual time variations in the position and intensity of storm tracks. The study builds on his previous work and is motivated by the observed suppression of the of the Pacific storm track in mid-winter. The research consists of four thrusts. The first three focus on how specific mechanisms affect eddy growth in a given basic state; the fourth concentrates on isolating and understanding the effect of storm track eddy fluxes on the basic state. Specifically, the PI wishes to investigate (1) the effect of the basic state shear on the baroclinic sources of storm tracks particularly the effect on upper-level perturbations coming off the Asian continent; (2) the modes of variability due to wave propagation variations; (3) the effect of condensational heating on storm tracks; and (4) the relationship between the amplitude and the location of storm tracks and low-frequency variability of the atmosphere. For this study, the PI will employ a combination of tools including observational data analyses, numerical simulations with General Circulation Models (GCMs), and idealized models. The fourth thrust will involve the coupling of a storm track model and a stationary wave model. This research is important because the location and intensity of storm tracks have direct bearing on regional weather. Further, a better understanding of storm track behavior is needed to anticipate potential changes that might result from climate variations.