Researcher at UMass Amherst Involved in Project to Improve Weather Forecasting, Air-Quality Models

AMHERST, Mass. - University of Massachusetts professor Stephen Frasier is one of 60 researchers from around the country participating this month in a research project aimed at improving weather forecasting. Over the course of the month, hundreds of red balloons are being released in the night air above Salt Lake City as part of an intensive study of how air moves. The study is expected to lead to improved computer models for air quality and weather forecasting, which would be especially useful in cities prone to smog.

The researchers are using more than 200 weather balloons; nine major instrument sites including three laser systems and six radar systems; dozens of meteorological ground stations; and a research plane to gather data throughout the Salt Lake City valley, covering roughly 460 square miles. Frasier''s students are operating two radar systems that track vertical airflows. They developed the systems in the University''s well-regarded Microwave Remote Sensing Laboratory.

"Remote sensing systems such as Doppler radar are increasingly important to scientists interested in improving atmospheric turbulence models, as they can provide coverage over larger volumes than is possible with direct measurements from the ground or from balloons," Frasier said. "As atmospheric models become more sophisticated, validating them also requires more detailed and sophisticated measurements." The radars developed by UMass are sensitive to subtle changes in humidity that often exist at the interfaces between air masses. Turbulent airflow is often present at these interfaces, so the structure of the flow can be observed by the radar.

The project is aimed at understanding how and where pollutants from energy production move in the atmosphere. "This study will focus on certain poorly understood atmospheric processes that affect how air mixes and moves vertically," said Chris Doran of the U.S. Department of Energy''s (DOE) Pacific Northwest National Laboratory, and lead scientist for the study. "Gaining a better understanding of how pollutant-trapping inversions form and break up has implications for improving air quality, weather forecasting and even aircraft operations."

Scientists are particularly interested in gathering data on how the atmosphere mixes at nighttime, in the evening and early morning, when the atmosphere is more stratified and there is less turbulence. The Salt Lake City valley''s topography is complex, providing a good setting to study how cold night air collects in mountain basins, said Doran. Cold air pools below warmer air, creating a temperature inversion that can trap pollutants. Learning more about the nighttime pooling effect should help predict the impacts of weather on an entire city in a basin region.

This month''s study is part of a four-year, $12-million effort sponsored by the DOE''s Office of Biological and Environmental Research. The combination of the setting, size of the effort, and the extent of the specialized instrumentation makes this study unique, according to the DOE. The study involves 14 different research organizations, including national labs, universities, government agencies, and private industries. Along with UMass, participants include: Argonne National Laboratory, Brookhaven National Laboratory, Los Alamos National Laboratory, Pacific Northwest National Laboratory, Arizona State University, Colorado Research Associates, Desert Research Institute, National Center for Atmospheric Research, National Oceanic and Atmospheric Administration''s (NOAA) Environmental Technology Laboratory, NOAA''s Atmospheric Turbulence and Diffusion Division, Oregon State University, Stanford University, and the University of Utah.

NOTE: Stephen Frasier may be contacted at frasier@ecs.umass.edu or 413/545-4582. Additional information is available on the World Wide Web at http://www.pnl.gov/vtmx.