Dr. James Davis is a research professor at Columbia University's Lamot-Doherty Earth Observatory, where he specializes in positional and physical geodesy--Earth's shape, orientation and gravitational field. This research finds direct application in studies of ice sheets, glacial movement, climate and the atmosphere. Other applications include geophysics, natural hazards, hydrology and geothermal energy. Davis has been a member of the Gravity Recovery and Climate Experiment (GRACE) team since 2003.