Massie is a chemist who uses satellite data to study the origins and movements of air pollutants and other atmospheric chemicals. He has looked into such issues as increased pollution emitted from Asia and smoke from intense boreal fires in Asia and North America. He also conducts research on polar stratospheric clouds that affect the ozone hole and on thin, high cirrus clouds that help to produce a dry stratosphere. Much of his recent work focuses on understanding a region high in the atmosphere, known as the tropopause, that can influence global climate by affecting the amount of solar radiation that reaches Earth. He is a researcher in NCAR's Atmospheric Chemistry Division.