AOS 651: Synoptic-Dynamic Laboratory:
Analysis, diagnosis, and prediction of
quasi-balanced atmospheric circulations
Fall 2005

Instructor:  Michael C. Morgan (mcmorgan@ wisc.edu)

Course description: This course focuses on the analysis, diagnosis, and prediction of quasi-balanced atmospheric flow phenomena - ranging from planetary-scale circulations to frontal-scale circulations. Lectures and problem sets develop the theory used to describe and diagnose these phenomena, while laboratory exercises involve the practical application of these analysis and diagnostic tools. While this is a laboratory class, particular emphasis is placed on developing a comprehensive understanding of the underlying the theory behind the various diagnostic tools developed as well as a comprehensive interpretation of the results obtained through application of these diagnostics. Students will develop diagnostic tools using FORTRAN and numerically solve some problems with Matlab.

Students are required to participate in the National Collegiate Weather Forecasting Contest.

Grading: Laboratory work and projects (60%), exams and quizzes (15%), problem sets (20%), class participation (5%)

Text and references: While there are no required textbooks for this course, a useful reference text is Mid-latitude Weather Systems by T. Carlson

In addition, several journal articles will be distributed which students are expected to read.

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Lecture

1) Data and analysis techniques

2) Review of basic dynamics

• Governing equations
• Hydrostatic balance
• Thickness and the thermal wind
• Circulation theorems

3) Barotropic dynamics and inversion of barotropic (potential) vorticity

4) Shallow water system, Rossby (geostrophic) adjustment

5) Quasi-geostrophic dynamics

• Underlying assumptions
• Conservation and invertibility of pseudo-potential vorticity
• Bretherton’s generalized PV
• Dynamic boundary conditions for invertibility
• Superposition principle

6) Ertel PV conservation and invertibility

7) Planetary-scale wave structure and dynamics

• Observations
• Rossby wave propagation (phase and group)

8) Cyclones and cyclogenesis

• Observations (structure, favored locations for growth, favored tracks)
• Mechanisms for cyclogenesis
• Eady model
• Effects of friction, topography, and latent heat release
• Diagnosis of cyclogenesis using piecewise PV inversion
• Air flow through cyclones (isentropic analyses)

9) Fronts and Frontogenesis

• Observations of surface and upper-tropospheric fronts
• Diagnosing frontogenesis
• Dynamics of frontogenesis (in QG and SG) frameworks
• Sawyer-Eliassen circulations
• Upper-tropospheric frontogenesis and jet streaks

10) Predictability of mid-latitude weather systems

• Sources of forecast error
• Diagnosing initial condition error
• Mechanisms for error growth

Problem Sets

1) Assimilation and analyses (what’s behind 3DVAR)

2) Eady-edge waves
3) Eady model (analytic and numerical solutions to the stability problem)

4) Barotropic instability
5) Transient growth

6) PV conservation

7) Mechanisms for frontogenesis

Laboratory exercises

1) Analyses and observations
2) Vorticity inversion
3) QGPV inversion
4) Non-linear balance PV inversion
5) QG w-equation
6) Isentropic analyses and trajectories
7) Sawyer-Eliassen frontal circulation
8) Forecast sensitivity