Amazon Rainforest Provides a Unique Natural Lab to Study Effects of Aerosols

Research funded by ASR on the power of aerosols is the focus of a new paper in the journal Science.  While scientists have known that aerosols may play an important role in shaping weather and climate, this study shows that the smallest of particles have a big effect: Particles smaller than one-thousandth the width of a human hair can cause storms to intensify, clouds to grow and more rain to fall.
Long considered too small to have much impact on droplet formation, aerosols are, in effect, diminutive downpour-makers. “We showed that the presence of these particles is one reason why some storms become so strong and produce so much rain. In a warm and humid area where atmospheric conditions are otherwise very clean, the intrusion of very small particles can make quite an impact,” said Pacific Northwest National Laboratory Earth Systems Analysis & Modeling Scientist Jiwen Fan.
As the paper’s lead author, she worked with 21 authors from 15 institutions around the world in this study.
The findings are based largely on unique data made possible by the GoAmazon2014/2015 research campaign, in which scientists made ground-based and airborne measurements related to climate. The GoAmazon campaign was managed by the Atmospheric Radiation Measurement (ARM) Climate Research Facility, a U.S. Department of Energy Office of Science user facility. Campaign funding was provided by ASR.

The study capitalized on data from an area of the Amazon that is pristine except for the region around Manaus, the largest city in the Amazon, with a population of more than 2 million people. The setting gave scientists the rare opportunity to look at the impact of pollution on atmospheric processes in a largely pre-industrial environment and pinpoint the effects of the particles apart from other factors such as temperature and humidity
Read the full Science paper.
# # #
This work was supported by the U.S. Department of Energy’s Office of Science, Office of Biological and Environmental Research as part of the Atmospheric System Research Program.