Clouds are the spark plugs in the heat engine of the tropical atmosphere, and heat from the tropics drives the planet’s general circulation. Atmospheric scientists didn’t know this in the 1950s, but Joanne Simpson, the first American woman to earn a Ph.D. in meteorology, did. Most histories of meteorology focus on polar and temperate regions and the accomplishments of male scientists. They marginalize or erase completely the contributions of female researchers. Joanne’s work on the tropical atmosphere did not fit this pattern. Joanne had a lifelong passion for clouds and severe storms. She flew into and above them, photographed them, modeled them, attempted to modify them, and studied them from all angles. She held two university professorships, married three times, had two lovers (one secret), mentored a generation of meteorologists, and blazed a trail for other women to follow. This book is about Joanne’s personal and professional life, her career prospects as a woman in science, and her relationship to the tropical atmosphere. These multifaceted and interacting textual streams constitute a braided narrative and form a complex dynamic system that displays surprising emergent properties. Is Joanne Simpson best remembered as a pioneer woman scientist or the best tropical scientist of her generation? She was both, with the emphasis on best scientist.