This volume is a summary of work undertaken since 1978 when I completed my doctoral dissertation at the Laboratoire de Meteorologie Dynamique (LMO) of the Ecole Normale Superieure in Paris. Since that time, my career has taken me through different countries and institutions, many of which have strong links to climate research in one form or another. It would be difficult to thank the numer- ous persons whom I have met in the course of my professional life and who contributed directly (for example as co-authors), or indirectly, to the papers which I have published in various journals. I am particularly indebted to Dr. Gilles Sommeria, who at the time was my thesis supervisor, for his advice during the preparation of my dissertation, and for his enthusiasm which encouraged me to take up a career in scientific research. My thanks also go to Prof. Ernst Augstein, Prof. Hans Hinzpeter, and Prof. Klaus Hasselmann for giving me the opportunity to carry out advanced research at the Max-Planck-Institute for Meteorology, from the early to mid-1980s.
