The Sun : An Introduction to MHD
a course given to final year undergraduates in 1999
You can access the Solar MHD Research group's page by clicking on the above. You will also find out information about PhD studentships here.
Information about the honours projects on solar physics is now available.
Solar Eclipse 1999
There will a full solar eclipse over the south-west of England in summer 1999. An interesting CD Rom is being produced to describe the Sun and the eclipse by researchers at St Andrews University.
The Sun course at St Andrews University provides an introduction to MHD,
(Magnetohydrodynamics), and a variety of interesting phenomena observed
on the Sun.
There are a large number of interesting Web sites with pictures of the Sun
and text to describe them. For example,
SDAC (the Solar Data Archive Center) provides the latest pictures of the
Sun with (i) Soft X-ray pictures from Yohkoh (ii) Photospheric magnetograms
(iii) He I and Ca II images and (iv) White light coronagraph pictures. In addition, the latest SOHO pictures can also be viewed.
These images are only one or two days old. An interesting slide set, plus descriptions of the slides, is available at the High Altitude Observatory in Boulder, Colorado. The Marshall Space Flight Center provides a good description of many solar features as well as information on various missions such as Yohkoh, Ulysses, SOHO and GONG. Some of these missions have their own home pages, such as Yohkoh, Ulysses, and SOHO.
There are many other sites that have pictures of the Sun and its atmosphere. Some of them can be found on the solar sites index.
Having seen the pictures, now read the lecture notes!
- General description
- Film or videos of Sun - shown at first tutorial
- Discuss some solar phenomena
- State electromagnetic equations - discuss importance for various terms
- State fluid equations - discuss (e.g. mass continuity equation), only simple energy eqn.
- Induction equation - diffusion
- Induction equation - frozen-in theorem
- Kinematic concentration of field lines
- Magnetic field lines
- Lorentz force - pressure and tension
- Plasma beta - low beta, high beta
- Hydrostatic pressure balance - isothermal, non-isothermal
- Potential fields
- Force-free fields (constant alpha and non-constant alpha)
- Force-free arcades
- Prominences (properties and model)
- Intense flux tubes and sunspots (properties and simple model)
- Grad-Shafranov equation
- Linearized ideal MHD equations - normal modes.
- Sound waves (acoustic) - dispersion relation, phase speed, group velocity
- Magnetoacoustic waves - application to line-tied fields.
5 Solar Flares (2 lectures)
- Collapse of X-Points
- Magnetic Field above Sunspots
- MHD Instabilities
- Flare Properties
Total of 25 lectures
- Parker's isothermal model (also adiabatic model)
- Grad-Shafranov equation - solutions.