The study of Earth's atmosphere is known as atmospheric science. It deals with the study of Earth's atmospheric processes, the effects other systems have on the atmosphere and vice versa. Meteorology is the branch of atmospheric science which involves atmospheric physics and chemistry with a focus on weather forecasting. The study of atmospheric changes is known as climatology. It involves the study of atmospheric changes which are both long-term and short-term. It also defines average climate and their changes over time due to both natural and anthropogenic climate variability. The study of upper layers of atmosphere where dissociation and ionization are important, fall under aeronomy. Rocketsondes, radiosondes, satellites, lasers and weather balloons are some of the experimental instruments used in atmospheric science. This book contains some path-breaking studies in the field of atmospheric science. The aim of this book is to present researches that have transformed this discipline and aided its advancement. As this field is emerging at a rapid pace, the contents of this book will help the readers understand the modern concepts and applications of the subject.