67111 - Planetary Atmospheres

Learning outcomes

At the end of the course the Student is able to analyze the planetary atmospheres as physical systems. He learns the phenomenology and equations governing the fundamental physical processes occurring in the planetary atmospheres. The Student is able to interpret simplemodels ofgreenhouse effect and to link climatic patterns with orbital parameters of Planets.

Course contents

1) Origin and composition of the Solar System Theories on the origin of the solar system. Main physical laws governing its configuration. The planets: active and inactive surfaces, internal structures. Satellites and rings. Minor bodies of the solar system: nanoplanets, asteorids, comets, meteorits. Transneptunian objects.

2) Main characteristics of the Earth and Planets atmosphereComposition and chemical evolution. Mass escape mechanisms (Jeans Escape). Mean thermal structure. The Stratosphere and the role of the Ozone layer. Thermal vertical profile of internal and external planets.

3) Thermodynamics of the Atmosphere Air parcel concept. The gas laws applied to the real atmospheres. Hydrostatic balance and hypsometric equation. Dry air: adiabatic processes and lapse rate. Diabatic processes and diabatic stratification.

4) Hydrostatic Stability Buoyancy force and vertical velocities. Static stability and the Brunt Vaisala frequency. Categories of static stability for dry air and convection. Auto-convective gradient.

5) Water Vapour and Condensed Phase in the Atmosphere Water vapour saturation pressure and phase changes. Adiabatic lapse rate for saturated air (pseudo-adiabats). Condensed states in atmospheric planets: clouds.

6) Fundamentals of Radiative Transfer Electromagnetic spectrum. Solid angle and main radiometric quantities. Black body radiance and its fundamental laws.Kirchhoff's law. The differential equation of the radiative transfer for absorbing and emitting processes.Schwarzschild's solution for a plane parallel atmosphere.

7) The Sun The structure. Luminosity and measure of the Solar Constant. The solar spectrum. Sun radiation and atmospheric particles and gas interaction.

8) Radiative Equilibrium and emission temperature of a Planet Albedo. Basic model for a planet in radiative balance. Emission temperature and variation of the solar constant and of the spherical albedo. Mean surface temperature and emission temperature.

9) Greenhouse Effect Greenhouse 1-d model. Greenhouse parameter. The Venus case and the Sandstrom theorem. Radiative equilibrium in a plane parallel and grey atmosphere.Runaway green-house effect (Venus, Earth and Mars). Time radiative constants.

10) Basic of atmospheric dynamics Basic equations. General circulation in the Earth atmosphere. Cases analysis: circulation on Venus, diurnal winds on Mars and convective processes on Jupiter.

11) Simple Climatic Models 0-d models and feedback processes. Energy balance 1-d climatic models: Budyko-Sellers.Milankovitch theory: orbital parameters and climatic patterns. Experimental data and glacial eras.

Readings/Bibliography

T. Maestri. Planetary Atmospheres. Available directly from the teacher.

C. Bartolini, M. Benelli, L. Solmi: DVD-ROM "Viaggio nel Sistema Solare" (2011) available at the Astronomy Dep.

John M. Wallace and Peter V. Hobbs. Atmospheric Science: An Introductory Survey Academic Press, 1997.

Joseph W. Chamberlain and Donald M. Hunten. Theory of Planetary Atmospheres: An Introduction to Their Physics and Chemistry Aca- demic Press, 1987.

D. L. Hartmann. Global Physical Climatology Academic Press, 1994.

Murry L. Salby Fundamentals of Atmospheric Physics Academic Press, 1996.

Teaching methods

The teacher will discuss the program content by using the blackboard and by exploiting the video projector. Simple exercises will be solved during the classes.

Assessment methods

Oral test and discussion of a brief research paper (prepared by the student) which analyze a specific topic.

Teaching tools

The following items will be available to the Students:
* Lectures notes (on paper and/or electronics).
* Scientific articles useful to the investigation of specific research lines.
* Software algorithms for the numerical solution of specific problems.
* Materials on dvd
* Bibliography and references

Office hours

See the website of Tiziano Maestri