A paper authored by three GFDL scientists, which tied weaker South Asian summer monsoons to human activities, has won the World Meteorological Organization’s Norbert Gerbier-MUMM International Award for 2013. The paper, “Anthropogenic aerosols and the weakening of the South Asian Summer Monsoon” was published in the journal Science in September 2011.
Coauthors Massimo Bollasina (Postdoctoral Research Associate), Yi Ming (Physical Scientist), and V. “Ram” Ramaswamy (Director), answered an important question about decreasing rainfall during South Asian summer monsoons in the last half of the 20th century. Monsoon rains provide about 80 percent of the precipitation for this region of the world, so weaker monsoons could prove harmful to crops, livestock, water resources, and human and economic health. Policymakers and resource managers needed to know whether the decreased rainfall was part of a natural cycle or was influenced by human activity.
Using the latest GFDL global climate model (CM3), the authors compared model simulations with observed monsoon rainfall data and hydrological cycle theory. The results clearly pointed to human influences as the driving force behind decreasing monsoons. However, increased concentrations of greenhouse gases in the atmosphere were not to blame for this observed phenomenon. Aerosols, or tiny particles emitted by the burning of fossil fuels, were. This research indicates the prominent role that aerosols can play in altering regional climate.
The three authors will receive the award next spring at the World Meteorological Organization in Geneva. The WMO is the United Nations’ agency for weather, climate, and water and serves the world community. The WMO established the annual Norbert Gerbier–MUMM International Award to “reward an original scientific paper on the influence of meteorology in a particular field of the physical, natural or human sciences, or on the influence of one of these sciences on meteorology.” The award was named for the late Norbert Gerbier, who served as president of the WMO Commission for Agricultural Meteorology from 1979 to 1985.