Instructor: Prof. Gregory Hakim (685.2439) (www)

Department of Atmospheric Sciences; University of Washington

This course provides an introduction to the fluid dynamics of the
extratropical atmosphere on synoptic (~1000 km) and larger scales.
Our main objective is to derive a simplified set of equations that capture
the dynamics on these scales, while providing a foundation for physical
understanding. Potential vorticity provides a useful framework to link
physical understanding of theory and observations. The simplified
equations are applied to: Rossby-wave propagation, baroclinic
and barotropic instability, and nonlinear dynamics (turbulence).

 
Prerequisites: ATMS509 (or OCEAN 512).

Class meets: MWF 12:30-1:20 p.m. in ATG 310C.

Syllabus

Written summary of class highlights.

Tom Galarneau's real-time QG diagnostics

Basic equations review.

Wave properties.

Synoptic overview (ppt).

Geostrophic adjustment.

PE Linear modes summary.

Observations of baroclinic waves.

Eady growth rate curve.

Eady phase speed curve.

Eady growing mode.

Eady decaying mode.

Meridional heat fluxes for growing and decaying modes.

Eady neutral mode (surface).

Eady neutral mode (tropopause).

Eady neutral modes (heat flux).

Eady singular neutral mode.

Random initial condition development.

Localized initial condition development.

Downstream development.

Comparison of QG, QG+1, and PE normal modes (from Rotunno et al. 2000).

Solution on the sphere (Thorncroft et al. 1992)

Solution on the sphere (Simmons and Hoskins 1978)

Zonal-mean energy cycle I (Simmons and Hoskins 1978)

Zonal-mean energy cycle II (Simmons and Hoskins 1978)

Peixoto--Oort energy cycle

Observational example of barotropic instability.

Growing barotropic mode.

Neutral barotropic modes.

Nonlinear barotropic instability.

Singular vector plot at t = 0 (k=2.5).

Singular vector plot at t = 10 (k=2.5).

Singular vector animation.

Nonlinear dynamics.