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Geophysical and Astrophysical Fluid Dynamics
This course explores fluid dynamics in stars, planets, and their atmospheres, through the lens
of nonlinear physics and advanced hydrodynamics. It focuses on transport phenomena,
instabilities, and the specific dynamical mechanisms that emerge in geophysical and
astrophysical systems, where rotation, stratification, turbulence, and electrical conductivity
play a central role. The aim is to unify our understanding of convection, turbulent transport,
magnetic field generation, and large-scale circulation, by combining theoretical insights with
observational and experimental results. Typical systems studied in this course include
convective/radiative regions of stars, planetary cores, the Earth’s atmosphere and oceans, as
well as accretion disks around black holes and protostars.
Syllabus
1. Heat transfer and convection in stars and planets
Stellar convection and planetary convection – compressibility effects and the Boussinesq
approximation – Mixing length theory
2. Turbulent transport
Turbulent heat transport and ultimate regime in stars and planets– Kraichnan’s scaling laws
– angular momentum transport in accretion disks – turbulent viscosity
3. Magnetohydrodynamics
Electrically conducting fluids – dynamo theory – geomagnetic field reversals – MHD
turbulence
4. Atmospheric and oceanic flows
Beta-plane approximation – geostrophic thermal wind – Baroclinic instability – nonlinear
waves and tsunamis
Evaluation
2h written exam
Prequisites
none