Physics of Geomagnetic phenomena, Volume I covers the significant advances in geomagnetism and the penetrations into the generation of geomagnetic field phenomena. This volume is composed of three chapters. Chapter I deals briefly with the discovery and developments in geomagnetism, followed by discussions on some fundamental topics of the field, including the aurora and geomagnetic storms. This chapter also considers the instruments, geomagnetic stations, and the correlations between geomagnetic indices. Chapter II describes the magnetic properties of minerals and various processes of acquisition of remanent magnetization. This chapter also provides palaeomagnetic data for the direction and intensity of the geomagnetic field in ancient times. Chapter III explores geomagnetic variations caused by solar flares and eclipses. This book will prove useful to physicists, students in upper atmospheric and space topics, and scientists in allied fields with a background in geomagnetism.