- Docente: Rolando Rizzi
- Credits: 8
- SSD: FIS/06
- Language: Italian
- Teaching Mode: Traditional lectures
- Campus: Bologna
-
Corso:
First cycle degree programme (L) in
Atmospheric physics and Meteorology (cod. 8008)
Also valid for First cycle degree programme (L) in Physics (cod. 8007)
Course contents
Thermodynamics of dry air: properties of mixtures, adiabatic
processes, potential temperature, thermodynamic diagrams, virtual
temperature, hypsometric relation, hydrostatic stability of
unsaturated air, stability categories.
Saturated behaviour and the release of latent heat, Normand's rule,
finite displacements and conditional instability, potential
instability.
Atmospheric composition: processes that influence the behaviour of
the atmosphere, the “mean” atmosphere, spatial distribution of
measuring stations, the mean atmospheric temperature profile,
variability of mean profile of pressure and molecular number
density, variability of mean temperature, mean composition of the
atmosphere, latitudinal and time variations of mean temperature,
meridional cross-sections of zonal temperature, meridional
cross-section of zonal wind, mean meridional circulation.
Basic radiative processes: electromagnetic waves, irradiance and
radiance, spectral radiance and irradiance, historical development
of Planck's radiation law, black body radiance and related
derivations, brighness temperature and temperature sensitivity,
solar energy flux, flux density, and solar constant, emission
temperature of a planet, absorption, reflection and transmission by
a slab of material, extinction of solar radiation, the langley
plot.
Absorption and emission: Kirckhoff law and spectral emittance,
thermodynamic equilibrium and local thermodynamic equilibrium, the
“greenhouse” effect.
The radiative transfer equation for absorption and emission, the
Schwarzschild's equation for a plane parallel atmosphere, an
introduction to the general rt equation, example of transmittances,
surface radiative properties, infrared irradiance in clear skies,
cooling and heating rates, short-wave clear-sky heating, long and
short wave clear-sky cooling and heating, an analytic model for the
greenhouse effect.
The Earth radiation budget: sun and the planets, the measurement of
solar irradiance, distribution of insolation, radiative balance at
TOA: definitions, intrinsic limitations and observing geometries,
poleward energy flux, global mean atmospheric energy balance.
Atmospheric turbulence. Speed, temperature, water vapour content
and concentrations as stochastic variables: probability density
function, moments, correlations and spectra.
Averaging procedure and equation formulation: filtered equations
and Reynolds averaged equations.
Universal properties of turbulence and inertial subrange
(Kolmogorov 1941). Dissipation. Turbulent dispersion.
The horizontally homogeneous planetary boundary layer.
Introduction to the similarity theory of the surface layer.
Readings/Bibliography
Atmospheric Science, An introduction John M. Wallace e Peter V.
Hobbs Academic Press.
Lecture notes in english (available in the web)
Teaching methods
Formal lectures. Exercises discussed and solved during class by the
students. Complex exercises (thermodynamics and radiative balance)
discussed and solved at the data analysis lab.
Assessment methods
Written report on lab activities. Final oral examination.
Teaching tools
Lectures using pc and projector. Class exercises and more complex exercises discussed and solved at the hands-on lab.
Office hours
See the website of Rolando Rizzi