This thesis begins with several chapters on the theory of the upper atmosphere and the technical details of the instruments and analysis methods that were used for this study. In Chapter 2 several topics on the physical properties of the earth's magnetosphere and ionosphere are discussed. Starting with Section 2.1, an outline of the general spatial structure and features of this system, such as the solar wind (2.1.1), the geomagnetic cavity that is formed through the interaction of the wind with the magnetic field of the earth (2.1.2) and the resulting plasma circulation (2.1.3), will be given. Important physical properties that determine the way measurements are made will be discussed in Section 2.2 on magneto-ionic theory, Section 2.3 on wave propagation in the ionosphere and plasma instabilities in Section 2.4.
This will lead us to Chapter 3 where the SuperDARN radar, the instrument this thesis is based upon, will be described in detail. Included in this part of the thesis are fundamental principles of radars used in ionospheric studies (3.1) as well as a specific description about the operation and analysis techniques of the SuperDARN HF radars in particular (3.3). Spectral analysis as it applies to this radar is discussed in detail in Section 3.5.2, because it is the mathematical method used to analyze the autocovariance functions measured by the radar.
Chapter 4 adds the description of the DMSP satellite and its data products. Discussed are the principles behind the particle data measurements (4.2) and how they are used in conjuction with radar measurements through estimation of the ionospheric conductivity (4.2.2) and ionization rate (4.2.3).
The discussion of all of these topics provides the background necessary for an understanding of the experimental results of Chapter 5. Although some sections of these introductory chapters are more targeted to an audience of novices to radar and atmospheric physics, many important details about the particular analysis methods will be mixed into more generic knowledge from the reference material that was used.
Following in Chapter 5 will be a presentation of experimental results from several events for which both radar and satellite data were available in the two months of January and February 1995 as listed in Section 5.1. The performance of the parametric spectral estimators on SuperDARN data will be analyzed (5.2). Nine events will be discussed in detail (5.4). Radar and satellite observations will be compared in an attempt to explain the phenomena. The description of each event will have the same structure and contain graphs of the same form to facilitate an easy comparison between events.
Chapter 6 will contain a summary of important observations that were made in the events. A discussion about physical processes in the ionosphere which produces the events with references to similar findings by other authors, will make this an important section of the thesis.
A short conclusion is presented in Chapter 7. Included in the Appendix is a description of the computer programs that were developed for the radar and satellite data processing.