Although interesting in its own right, due to the ever increasing use of satellites for communication and navigation, weather in the ionosphere is of great concern. Every such system uses trans-ionospheric propagation of radiowaves, waves which must traverse the often turbulent ionosphere. Understanding this turbulence and predicting it are one of the major goals of the National Space Weather program. Acquiring such a prediction capability will rest on understanding the very topics of this book, the plasma physics and electrodynamics of the system. This book is fully updated to reflect advances in the field in the 20 years since the first edition was published. It explores the buffeting of the ionosphere from above by the sun and from below by the lower atmosphere. The unique text is appropriate both as a reference and for coursework.