Tim Killeen, an AMS Member, and a Fellow of the AMS, is the National Science Foundation Assistant Director for the Geosciences in Arlington, Virginia. Dr. Killeen oversees the Geosciences Directorate, which supports research in the atmospheric, earth, and ocean sciences, including climate processes and changes, the water cycle, and natural disasters such as earthquakes, tsunamis and severe storms. Before moving to NSF, Dr. Killeen was the Director of the National Center for Atmospheric Research in Boulder, Colorado from 2000 to 2008. As NCAR Director he had overall responsibility for the scientific, technical, and educational activities of NCAR, which has extensive observational and computational facilities that are used to support basic and applied research in atmospheric and related sciences on behalf of the university community. Dr. Killeen was also a senior scientist at NCAR's High Altitude Observatory where he led an experimental and theoretical program in upper atmosphere research. Prior to his move to NCAR, Dr. Killeen was full Professor of Atmospheric and Space Sciences at the University of Michigan. He was the Director of the UM's Space Physics Research Laboratory from 1993 to 1998 and Associate Vice President for Research from 1997 to 1999. Dr. Killeen led a research group of scientists and engineers working in the field of aeronomy, using a combination of theoretical and experimental techniques to investigate the dynamics, chemistry and composition of the upper atmospheres of the Earth and other planets. Dr. Killeen has authored over 140 publications in refereed journals. Dr. Killeen, a U.S. citizen, received a B.Sc. degree in physics in 1972 and a Ph.D. degree in atomic and molecular physics from University College London in 1975.