The global hydrological cycle links precipitation, evaporation, surface waters and atmospheric transports of water vapor.  Its behavior is crucially important to all life on Earth, including (and maybe particularly) human life.  It is generally agreed that global warming related to human-induced changes in atmospheric composition is underway, and that that warming will affect the elements of the hydrological cycle.  In this presentation, I will discuss the ways in which we can observe those elements, and compare the results to those obtained from global climate modeling studies and theoretical analyses.  I am particularly interested in comparing uncertainties in our observations to assumptions and simplifications in theory and models.

Lecturer
Dr Phillip A Arkin, Director of the Cooperative Institute for Climate and Satellites (CICS) at the Earth System Science Interdisciplinary Center (ESSIC) of the University of Maryland

Biography
Dr Arkin is Director of the Cooperative Institute for Climate and Satellites (CICS) at the Earth System Science Interdisciplinary Center (ESSIC) of the University of Maryland, where he also serves as Deputy Director and Senior Research Scientist.  He conducts research into the observation and analysis of precipitation and other aspects of the hydrological cycle of the global climate system in addition to his administrative duties.  Until January 2002, he served as Program Manager for Climate Dynamics and Experimental Prediction in the Office of Global Programs at NOAA, where he managed the Applied Research Centers that provide the research and development that enable NOAA to provide better climate forecasts.  From 1998-2000, he served as the Deputy Director of the International Research Institute for Climate Prediction (IRI) at Columbia University.  He spent 25 years working at NOAA as a research scientist and administrator in various parts of the climate community, including the Climate Prediction Center, the Office of Global Programs and the National Centers for Environmental Prediction.  He invented the GOES Precipitation Index, a method for estimating rainfall from geostationary satellite observations, and created the Global Precipitation Climatology Project and led it from 1985-1994.