Planetary Atmospheres (PlanAt | INU7045U)

Description: Comparison of the Planetary Atmospheres (2 lectures)
The radiative energy balance of a planetary atmosphere; the competition between gravitational attraction and thermal escape processes. The factors which influence planetary atmospheres; energy and momentum sources; accretion and generation of gases; loss processes; dynamics; composition.

Atmospheric structure (7 lectures)
Hydrostatic equilibrium, adiabatic lapse rate, convective stability, radiative transfer, the greenhouse effect and the terrestrial planets.

Oxygen chemistry (3 lectures)
Ozone production by Chapman theory; comparison with observations; ozone depletion and the Antarctic ozone hole.

Atmospheric temperature profiles (3 lectures)
Troposphere, stratosphere, mesosphere, thermosphere and ionosphere described; use of temperature profiles to deduce energy balance; internal energy sources; techniques of measurement for remote planets.

Origin of planetary atmospheres and their subsequent evolution (3 lectures)
Formation of the planets; primeval atmospheres; generation of volatile material; evolutionary processes; use of isotopic abundances in deducing evolutionary effects; role of the biomass at Earth; consideration of the terrestrial planets and the outer planets.

Atmospheric Dynamics (4 lectures)
Equations of motion; geostrophic and cyclostrophic circulation, storms; gradient and thermal winds; dynamics of the atmospheres of the planets; Martian dust storms, the Great Red Spot at Jupiter.

Magnetospheric Effects (1 lecture)
Ionisation and recombination processes; interaction of the solar wind with planets and atmospheres; auroral energy input.

Atmospheric loss mechanisms (1 lecture)
Exosphere and Jeans escape; non thermal escape processes; solar wind scavenging at Mars.

Observational techniques (3 lectures)
Occultation methods from ultraviolet to radiofrequencies; limb observation techniques; in-situ probes.

Global warming (3 lectures)
Recent trends and the influence of human activity; carbon budget for the Earth; positive and negative feedback effects; climate history; the Gaia hypothesis; terraforming Mars.

This module is taught at UCL.