Module Identifier PH39010  
Module Title IONISED ATMOSPHERE  
Academic Year 2004/2005  
Co-ordinator Dr Andrew R Breen  
Semester Semester 2  
Other staff Dr Andrew R Breen, Dr Eleri Pryse  
Pre-Requisite PH29010 , Core Physics Modules at Level 2  
Course delivery Seminars / Tutorials   2 seminars/tutorials  
  Lecture   20 lectures  
Assessment
Assessment TypeAssessment Length/DetailsProportion
Semester Exam2 Hours end of semester examination for BSc students  100%
Semester Exam3 Hours end of semester examination for MPhys students  100%

Learning outcomes

After taking this module students should be able to:

Brief description

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.

Content

Introduction: The ionosphere at mid and low latitudes: D, E and F regions, ionisation production and loss mechanisms, Chapman layers. Observed 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, phase velocity, group velocity, refractive index. Applications of the Appleton equation, ionosondes, transionospheric 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; magnetic perturbations in the auroral zone.

Reading Lists

Books
** Reference Text
R.D. Hunsucker Radio Techniques for Probing the Terrestrial Ionosphere Springer-Verlag
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
May Britt Kallenrode (2001) Space Physics Springer-Verlag
W. Baumjohann and R.A. Treumann (1997) Basic Space Plasma Physics Imperial College Press

Journals
B. Hultqvist, M. Oierostt, G. Paschmann & R. Treumann (eds) (1999) Magnetospheric Plasma Iounces and Losses Space Science Reveiws, Vol 88

Notes

This module is at CQFW Level 6