New Study Reveals and Quantifies Magnitude of Long-term Aerosol Effects on Clouds and Precipitation
A study published in Nature Geoscience this week reveals a trend that atmospheric scientists have been mulling for decades: the effects of aerosols on clouds and rainfall. Some studies have suggested that aerosols—tiny particles in the air, such as dust and soot—may make clouds “drier” while others studies suggest they may intensify storm systems.
According to Zhanqing Li, a professor of atmospheric and oceanic science at the University of Maryland and lead author of the study, the new study reveals impacts of an “unprecedented magnitude.”
The findings, based on a 10-year data set of ground-based measurements from the ARM Southern Great Plains site in Oklahoma, corroborate an analysis of NASA global satellite products. Matching results were obtained from simulations by a cloud-resolving model. This is a computer model that simulates the regional-scale dynamics that occur in clouds, as opposed to the large-scale processes simulated in global climate models.
The work by Li and his research colleagues signifies the importance of long-term data sets for climate-relevant studies, as well as the need for measurements from regions of the world most affected by increasing levels of atmospheric aerosols, such as those obtained in these recent ARM field campaigns:
- Ganges Valley Aerosol Experiment, Nainital, India - 2011
- Clouds, Aerosol and Precipitation in the Marine Boundary Layer, Graciosa Island, Azores – 2009-2010
- Study of Aerosol Indirect Effects in China, Shouxian, China – 2008
- Journal of Geophysical Research-Atmospheres, Special Issue
For more information on the recent study, read the joint press release from Maryland, Brookhaven National Laboratory, and Pacific Northwest National Laboratory.
Article Reference: Li, Z., F. Niu, J. Fan, Y. Liu, and D. Rosenfeld, Y. Ding. 2011. "The long-term impacts of aerosols on the vertical development of clouds and precipitation." Nature Geoscience, doi: 10.1038/NGEO1313.