Richard Flagan
California Institute of Technology, CA·Earth & Environmental Science
Tiny particles suspended in air, called aerosols, seed the droplets that make up clouds, so how new particles form from gas molecules helps set cloud cover, rainfall and how energy moves through the atmosphere. This is one of the least certain pieces of climate and weather prediction, because the first steps, a handful of molecules sticking together into a stable cluster, are hard to catch in the open atmosphere.
- Fields
Earth & Environmental Science
Chemistry
Engineering
- Topics
aerosols
new particle formation
nucleation
- Grants
- 1 known grant, through Dec 2028
What they work on
- Develop molecular-level descriptions of how new atmospheric particles form and grow, using controlled experiments in the 26 cubic meter CLOUD chamber at CERN with regulated temperature and relative humidity.
- Measure particle formation from gas mixtures relevant to the upper atmosphere, including sulfuric and nitric acids, ammonia and other bases, and iodine oxidation products.
- Translate chamber results into parameterizations, simplified formulas describing particle formation rates, for use in atmospheric and climate models.
- Use CLOUD campaigns as a test bed to develop and evaluate new instrumentation for detecting and characterizing freshly formed aerosol particles and molecular clusters.
More about the research
This project supports continued U.S. participation in the CLOUD (Cosmics Leaving OUtdoor Droplets) consortium at CERN, which runs a 26 cubic meter stainless-steel chamber with tight control of temperature and humidity; no facility in the United States has these capabilities.
Why it matters
Clouds and aerosols are among the largest sources of uncertainty in forecasts of weather and future climate. Measuring how particles form from specific gases, and converting those measurements into formulas models can use, could make projections of cloud behavior and atmospheric conditions more reliable, information that feeds into climate assessments and air-quality understanding. The chamber work also pushes the development of instruments able to detect newly formed particles.
Known grants
From NIH and NSF research grants. Labs often have other funding we can't see.
Closest labs
Hamish Gordon
Carnegie Mellon University, PA·Earth & Environmental Science·Early-career
Develop a new parameterization of atmospheric new particle formation that accounts for temperature and ions, using CERN CLOUD chamber data and field measurements, and evaluate it in climate models.
Brandon Boor
Purdue University, IN·Engineering·Early-career
Investigate how organic nanoaerosols, airborne particles smaller than 100 nanometers, form indoors down to molecular length scales, using advanced aerosol instrumentation to observe nucleation events.
Timothy Bates
University of Washington, WA·Earth & Environmental Science
Extend the 15-year Utqiaġvik record of submicron inorganic aerosol components, and analyze and archive 12 years of filter samples to build a nearly 30-year record.
The school
California Institute of Technology: 18 labs on PI Pages, $445M a year on research, 200 research doctorates a year.
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