22507 - Synoptic Metereology and Weather Forecasting

Learning outcomes

At the end of the course the student: - knows the basics of synoptic meteorology and can use his theoretical knowledge to understand the phenomena typical of these scales of motion; - knows the basic numerical methods for the solution of the equations of motion; - uses the outputs numerical weather forecast models (both global and limited area) for making weather forecasts; - acquires abilities in comunication on the subject and becomes familiar with the english terminology used in climatology; - learns how to use scientific literature

Course contents

introduction. What is synoptic meteorology? Instruments and observing networks. Global circulation.Examples from satellite pictures. Main differences between circulation near tropics mean and high latitudes. Hadley circulation. Conversion of APE in kinetic energy. Extra tropical cyclones. Brief history and characteristics. Model of the Bergen school and its limits. Ground and upper level characteristics of extratropical cyclones and cyclones in the lee of the mountains. Characteristics of fronts associated to extratropical cyclones. Description and fenomenology of Blocking. Equations of motion. Forces acting on a geophysical fluid. Scale analysis for horizontal motions at synoptic scale and geostrophic balance. Scale analysis for vertical motions at synoptic scale and hydrostatic balance. Pressure as vertical cohordinate. Continuity equation. Continuity equation in pressure cohordinates. Thermal wind. Thermodynamic equation and static stability. Waves in fluids. Surface waves in non rotating and rotating fluids. Barotropic and baroclinic fluids. Conservation of vorticity in barotropic fluids. Conservation of potential vorticity. Circulation. Free and forced Rossby waves. Examples of numerical solutions of the equation of conservation of vorticity. Dispersion and stability of waves. Kelvin-Helmholtz instability. Baroclinic instability. Planetary boundary layer. Reynolds mean, flux terms In turbulent flows, closure problems. Numerical integration of the diffusion equation. Example of numerical instability. CFL criterion. Example of unresolved spatial scales and noise due to truncation errors. Numerical methods for the solution of the equation of motion. Horizontal discretization. Staggered grids, spectral methods. Vertical discretization. Sigma cohordinates, theta eta hibrid. Physical parametrizations in numerical models. Radiation, PBL turbulent fluxes, ground effects, large scale and convective precipitation.

Readings/Bibliography

J.M. Wallace and P.V. Hobbs, "Atmospheric Science an introductorysurvey", Academic press. ISBN 0-12-732950-1.
J.R.HoltonN, "An introductio to dynamic meteorologyY", Academic press. ISBN0-12-354355-X

Teaching methods

Lectures and exercises

Assessment methods

Oral examination.

Teaching tools

Lecture notes available on line in the web site of the Corso di Studi

Office hours

See the website of Ennio Tosi