|Module Title||IONISED ATMOSPHERE|
|Co-ordinator||Dr Eleri Pryse|
|Other staff||Professor Shadia Habbal, Dr James Whiteway|
|Pre-Requisite||PH29010 , Core Physics Modules at Level 2|
|Course delivery||Lecture||20 lectures|
|Seminars / Tutorials||2 seminars/tutorials|
|Assessment||Exam||End of semester examinations||100%|
The presence of ionisation in the upper atmosphere was postulated to account for long distance radio wave propagation. Subsequent research established the existence of the ionised atmosphere and investigated its morphology. Active research continues to study ionospheric behaviour, in particular at high latitudes where the aurorae are a spectacular optical manifestation of incoming particles from space.
The morphology of the ionosphere is described, the production and loss processes of ionisation under normal conditions are explained, and the effects of neutral winds and electric fields are considered. An introduction is given to the influence of the ionosphere on radiowaves. The high latitude ionosphere is decribed in terms of magnetosphere processes mapped down the geomagnetic field.
After taking this module students should be able to:
Introduction: The ionosphere at mid and low latitudes: D, E and F regions, ionisation production and loss mechanisms, Chapman layers. Observes behaviours of the mid latitude ionosphere and the equatorial ionosphere. Motions of charged particles: effects of the neutral-air wind electric field.
Radiowave Propagation: Plasma frequency, gyrofrequency, Debye length, phase velocity, group velocity, refractive index. Applications of the Appleton-Hartree equation, ionosondes, trans-ionospheric propagation.
The High-Latitude Ionosphere and the Magnetosphere: the high-latitude ionosphere as a map of processes in the magnetosphere; the precipitation of energetic particles and the aurora; magnetospheric electric fields and the eastward and westward electrojets; megnetic perturbations in the auroral zone.
** Reference Text
J.K. Hargreaves. The Solar-terrestrial Environment. Cambridge University Press
K. Davies. Ionospheric Radio. Peter Peregrinus Ltd. for IEE
M.G. Kivelson and C.T. Russell (Eds). An Introduction to Space Physics. Cambridge University Press
R.D. Hunsucker. Radio Techniques for Probing the Terrestrial Ionosphere. Springer-Verlag