55216 - Dynamic Meteorology

Learning outcomes

The purpose of the course of Dynamic Meteorology is to provide a learning of the basic dynamical processes underlying the general atmospheric circulation and its variability on relatively short time scales. Such variability is associated with the evolution of meteorological phenomena and with the practical problem of short and medium range weather forecasting. The main topics of dynamic meteorology are treated, regarding the general circulation and the synoptic scale and mesoscale phenomena. The equations of motion, their properties and analytical or numerical solutions are analysed, including waves, instability processes, nonlinear effects and the principles of meteorological modelling. The  presentation of various theoretical aspects is conducted in parallel with the examination of the properties revealed by the analysis of observational data.

Course contents

Historical elements on the development in Dynamic Meteorology and numerical weather forecasting.

Overall characteristics of the global circulation derived from the ERA-40 reanalysis.

Principal phenomena of the atmospheric circulation, spectral analysis and classification on the basis of the various space-time scales.

Equations of motions on the sphere and related scaling.

Coordinate transformations and equations in isentropic coordinates.

Ertel's theorem and conservation of potential vorticity.

Circulation and related theorems (Kelvin, Bierknes); circulation and vorticity.

Dynamical and diagnostic applications of potential vorticity.   

Atmospheric wave dynamics: sound, gravity, Rossby waves; free and forced (by orography and thermal in-homogeneities) waves.

Flows over topography, orographic waves, flow regimes.

Quasi-geostrophic approximation.

Properties and variability of the extra-tropical circulation.

Baroclinic instability and the Eady model.

Examples and evolution of the mid-latitude baroclinic perturbations: cyclones, anticyclones and related conceptual models.

Storm-track characteristics and asymmetries of the zonal circulation.  

Low frequency variability: orographic instability and resonance; regime transitions; teleconnections.

Main circulation types relevant for the European and Mediterranean meteorology. Orographic cyclogenesis and Mediterranean cyclones: phenomenology and models.

Baroclinic instability modified by orography.

Effects of orography on the evolution of cyclones in mid latitudes.

Finite amplitude effects and water cycle effects on the extra-tropical cyclones.

Mesoscale structures of the extra-tropical cyclones: fronts, warm and cold conveyor belts, associated precipitating systems.

Surface and upper level fronts and frontogenesis.

Condensation/evaporation processes and their importance in mesoscale dynamics.

Dynamics of intense moist convection and mesoscale convective systems.

Simulation and forecasting meteorological models: examples of applications to idealized and real cases.  

Readings/Bibliography

J. Holton: Introduction to Dynamic Meteorology (Academic Press).

H.B. Bluestein: Synoptic-Dynamic Meteorology in midlatitudes (2 vol., Oxford Univ. Press).

E. Kalnay: Atmospheric modeling, data assimilation and predictability (Cambridge U. Press).

Transparencies and minutes of lectures (available online in pdf format, basically in English)

Teaching methods

The general topics of the course are presented and discussed during lectures, with practical demonstrations and classroom exercises that use observational data, maps and outputs from numerical models.

Assessment methods

The verification is based on the final oral exam, that will be based on a series of questions aimed at assessing the learning and understanding, by the student, of the conceptual, analytical and phenomenological elements treated in the course lectures.

Teaching tools

PC, overhad projector, Internet.

Links to further information

http://www.isac.cnr.it/dinamica/buzzi/lezioni_Meteorologia_Dinamica/

Office hours

See the website of Andrea Buzzi