The focus of this work is to understand the clouds and climates of the terrestrial planets including Venus, and Mars, and to better understand the habitability of planets. Graduate student Kevin McGouldrick is studying the lower clouds of Venus to explain the clearings in the clouds that occasionally occur at near infrared wavelengths as observed, for example, by Galileo spacecraft instruments. Another student, Attila Elteto, is developing a new technique for parameter retrieval from Mars Global Surveyor Thermal Emission Spectrometer data. He is modeling the response of observable infrared spectrum to variation in physical parameters, and then compares the model to the data to extract the physical conditions that exist in the Martian atmosphere.
During the past Dr. Toon has also investigated the environmental perturbations that would occur on Earth if it were struck by asteroids or comets of various sizes. Dr. Toon found that distinctly different phenomena occur in various size ranges. This study is designed to help guide astronomical searches for dangerous objects, and to shed further light on past impacts such as the one at the K-T boundary Dr. Tony Colaprete, now a Resident Research Associate at NASA Ames, has completed studies of the formation of carbon dioxide clouds in the atmosphere of Mars. These studies show that snowstorms occur on Martian wave clouds, and that ancient CO2 clouds were not efficient at warming the surface. He has also developed a model of water-ice clouds on Mars and applied it to Pathfinder, and Mars Global Surveyor data. Dr. Teddy Tian is studying the ancient atmosphere of Earth. Of interest in this case is the degree to which reducing gases may have been present. Mr. Kaj Williams is modeling Martian ice in order to understand possible mid-latitude gully formation mechanisms.
Specific topics and projects