Instructor: Prof. Richard Kleeman (Office: 901 Warren Weaver)
Location: 1013 Warren Weaver
Time: Tuesday 1:25-3:15pm, Spring 2008.
Basic Text:  J.R. Holton, “An Introduction to Dynamic Meteorology”, Academic Press, 1992.
Secondary Text: A.E. Gill, “Atmosphere-Ocean Dynamics”, Academic Press, 1982.
 

Assessment: 40% Assignments (3); 40% Final Examination (Take Home) and 20% Class Attendance.

There will be 13 lectures. The contents are described approximately below. Latex versions of the lectures will appear during the term and will be linked below.

Lecture 1: The basic equations for the atmospheric fluid.
The fundamental equations governing atmospheric flow will be derived and carefully explained. Approximations commonly used such as the hydrostatic and  incompressibility will be introduced and evaluated. Conservation laws for mass, energy and moisture will be derived and discussed.
 

Lecture 2: The forcing terms for the primitive equations.
External and internal forcings of the atmosphere are responsible fundamentally for the setting up of the observed mean circulations. The processes causing this forcing are primarily radiation, moist convection and turbulent transport. These are commonly described as physical processes and are modeled using physical parameterization. The nature of these forcings will be introduced and their importance for the atmospheric circulation motivated.
 

Lecture 3: Circulation and Vorticity.
Circulation and vorticity are the primary measures of rotation in a fluid such as the atmosphere. Understanding these concepts is basic to dynamical theories of geophysical flows. We derive the circulation theorems and the conservation equations for potential vorticity. Potential vorticity is explored in both a vertically uniform and non-uniform context. The latter form is referred to as Ertel's potential vorticity.
 

Lecture 4: The Planetary Boundary Layer.
The layer of the atmosphere close to the surface (within 1km) is subject to vigorous turbulent motion. Understanding how momentum is dissipated from the atmosphere by this process and how heat is acquired from the surface is crucial for an analysis of the mean atmospheric circulation is. The nature of the boundary layer and its effects on the interior of the atmosphere are examined.
 

Lecture 5: Quasi-geostrophic analysis.
The primitive equations are generally very difficult to analyse in a transparent way so various approximations are usually resorted to in order to further understanding. In the extratropics a particularly useful approximation is the quasi-geostrophic. The mathematics of this are carefully introduced and applied to understanding the mid-latitude atmosphere.
 

Lecture 6: Linear perturbation analysis and instability theory.
Another particularly useful methodology for the analysis of the atmospheric circulation is the linearized solutions of the primitive equations. Various wave-like disturbances may be derived and these play a basic role in our current understanding of the atmosphere. When the linearization is about a non-zero mean state, energy may be transferred from the mean flow into growing disturbances. The linear framework here is called instability theory.
 

Lecture 7: Baroclinic and Barotropic Instability.
The observed mean flow of the atmosphere is unstable mainly as a result of intense narrow flows called the jetstreams. The perturbations that grow as a result of this instability are responsible for frontal storm systems. Other instabilities of the mean flow are thought responsible for such mid-latitude variability as blocking where weather patterns remain stationary for many days. Linear instability analysis allows us to gain detailed physical understanding of these important forms of weather variability. Other analytical tools such as the Eliassen-Palm flux are also introduced to further understanding.
 

Lecture 8: The General Circulation: Basic Tools.
The nature of the mean circulation of the Earth's atmosphere is now reasonably well understood. In this lecture the basic machinery required for this understanding is introduced.
 

Lecture 9: The General Circulation: The zonally averaged circulations.
Basic latitudinal flows characterize the mean atmospheric circulation. The Hadley Cell is directly forced while the Ferrel Cell is driven mainly by the perturbations discussed in Lecture 7. Models of these fundamental circualtions are considered.

Lecture 10: Tropical Dynamics.
In the vicinity of the equator, atmospheric dynamics are different to the mid-latitudes due to the vanishing of the Coriolis force and the presence of moist convection. A survey of the appropriate dynamical machinery will be given.

Lecture 11: Forced Teleconnections.
Significant internal forcing anomalies often occur for extended periods in the deep tropics in association with the El Nino phenomenon. This forcing causes a large wave-like response to propagate to higher latitudes where it causes climate disturbances. The dynamcal nature of this response is examined.

Lectures 12 and 13: Predictability.
The concept of chaos was first introduced by a meteorologist (E. Lorenz of MIT) because the turbulent nature of the atmosphere means that detailed weather predictions beyond 14 days are impossible. Basic mathematical machnery to analyse predictability is introduced. The behaviour of simple models is used to illustrate general problems and outstanding issues.