Atmospher Sci & Global Chg
Research Highlights

November 2011

The Pollution, Cloud, Climate Connection

Pollution particles contribute to a storm cloud brewing over the cloud radar instruments at the Southern Great Plains site in Oklahoma. Photo courtesy of the U.S. Department of Energy ARM Climate Research Facility.
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Results: Increased air pollution changes clouds in ways that both worsen drought and increase storm intensity, according to new research published in the journal Nature Geoscience. A research team at Pacific Northwest National Laboratory, the University of Maryland, Beijing Normal University, Brookhaven National Laboratory and the Hebrew University of Jerusalem found that increases in air pollution’s tiny particles in the atmosphere have a strong influence on cloud development, which affects weather and climate. Researchers used 10 years of atmospheric site measurements, confirming those results using a cloud-resolving computer model.

This new research shows the first clear evidence of the long-term effects of pollution particles on cloud height and thickness, and how those changes both reduce precipitation in dry regions and increase precipitation in wet regions. A decade of observational data was collected at the ARM Climate Research Facility Southern Great Plains site in Oklahoma.

"The model simulations provide a strong theoretical support for the decade-long observational data," said Dr. Jiwen Fan, atmospheric scientist at PNNL. "The model simulations can isolate factors and explain the complex microphysical interactions in clouds that cannot be directly observed."

For more information, see the PNNL news release, "Rising Air Pollution Worsens Drought, Flooding," and Nature Geoscience.

Acknowledgments:

Funding: This research was funded by the U.S. Department of Energy's Office of Science, NASA, the National Science Foundation, and the Chinese Ministry of Science and Technology. The Atmospheric Radiation Measurement (ARM) Climate Research Facility is a DOE scientific user facility.

Research Team: The research was done by Zhanqing Li, Feng Niu and Yanni Ding of the University of Maryland; Jiwen Fan of PNNL; Yangang Liu of Brookhaven National laboratory; and Daniel Rosenfeld of the Hebrew University of Jerusalem, and is published in the November 13 issue of Nature Geoscience.

Reference: Li Z, F Niu, J Fan, Y Liu, D Rosenfeld and Y Ding. 2011. "Long-term impacts of aerosols on the vertical development of clouds and precipitation." Nature Geoscience, November 13, 2011. DOI 10.1038/NGEO1313.