Dr. William C Malm is a highly regarded research scientist/scholar at Colorado State University's Cooperative Institute for Research in the Atmosphere (CIRA). Previously he was at the National Park Service Air Resources Division where he was program coordinator for the visibility/particulate research and monitoring program. Prior to that, he worked as an Environmental Protection Agency (EPA) research scientist and as a Professor of Environmental Science at Northern Arizona University in Flagstaff. He is a member of the Air & Waste Management Association (AWMA), the American Geophysical Union (AGU), and the American Association for Aerosol Research (AAAR). He has served as an organizing chair for special sessions in each of these associations and as a guest editor for the Journal of Geophysical Research (JGR) and the Journal of the Air & Waste Management Association (JAWMA). He is also a topic editor for environmental monitoring for the Encyclopedia of Earth