WASHINGTON, D.C. -- The role of water vapor in the Earth's climate system will be discussed at a scientific conference organized by the American Geophysical Union in Potomac, Maryland, October 12 to 15. Scientists will concentrate on developments since the last such conference five years ago, a period during which theoretical and observational advances have been made.
Water vapor is the most abundant greenhouse gas and therefore significantly affects climate. It is involved in the global hydrological cycle, affecting both evaporation and precipitation. It participates in chemical reactions both in the troposphere, or lower atmosphere, where it is the major source of the hydroxyl (OH) radical, and in the stratosphere, which begins 6-10 miles (10-16 kilometers) altitude, where it affects the quantity of ozone (O3). But, despite water vapor's importance, its distribution and variability has not been as well studied as scientists would wish.
One of the conference goals is to bring together specialists in the troposphere and the stratosphere, according to Dr. Dian Gaffen of the National Oceanographic and Atmospheric Administration (NOAA) in Silver Spring, Maryland. Gaffen is one of the conference's conveners, along with Rebecca Ross, also of NOAA, and Dr. John Gille of the National Center for Atmospheric Research (NCAR) in Boulder, Colorado. Over 80 participants are expected from the United States and abroad.
In Potomac, a suburb of Washington, D.C., atmospheric scientists will focus on three major themes:
1. Water vapor and the greenhouse effect. At the 1995 conference, the notion that water vapor might have a negative feedback on the greenhouse effect evoked some controversy. Since then, considerable effort has been made to clarify this issue, and results will be presented at the conference.
2. The global hydrological cycle, i.e., the precipitation and evaporation of
water in the atmosphere. Extreme precipitation events, both flood-producing
Contact: Harvey Leifert
American Geophysical Union