Physics of Geomagnetic Phenomena, Volume I is a comprehensive, balanced, and authoritative introductory text to geomagnetism. The book is divided into three parts encompassing 11 chapters that discuss the advances in geomagnetism, the generation of geomagnetic field phenomena, and the geomagnetic storm generation mechanisms. The first part of the book covers the history, instrumentation, local anomalies, and different types of indices of geomagnetism. The second part discusses the paleomagnetic data for the direction and intensity of the geomagnetic field in ancient times, and then presents an outline of the theoretical interpretations of the main paleomagnetic results. This part also examines earth's main geomagnetic field and electromagnetic induction. The third part describes the morphologies of solar quiet and lunar daily variations on individual days and on the average, including the methods of obtaining current systems responsible for these variations and their results. Discussions on the geomagnetic variations in the equatorial zone; the neutral atmosphere and the quiet ionosphere; and the various geomagnetic and ionospheric phenomena are also provided.