Understanding atmospheric aerosols is important to understanding the effects of aerosol on climate, atmospheric composition, air quality, and human health. There are high uncertainties in the current global climate predictions largely because of our limited understanding of aerosols and clouds.
Nucleation is a gas to particle conversion process in which solid or liquid aerosol particles form directly from gas phase species and thus is an important step in the chain reactions that lead to cloud formation, but the mechanisms are poorly understood. Current nucleation theories are also hampered by high uncertainties because of the lack of laboratory and atmospheric measurements. Our research is designed to overcome some of these shortcomings in the field to yield a better understanding of aerosol formation processes in the atmosphere.
Kent State University Atmospheric Chemistry Group is equipped with a series of world-class, state of art chemical and aerosol instruments, including two Chemical Ionization Mass Spectrometers (CIMS)
that measure low concentrations of sulfuric acid, ammoni and amines; three Scanning Mobility Particle Spectrometers (SMPS); and a particle size magnifier (PSM, Airmodus) which measures sub-3 nm particles and clusters.
we have a proton transfer mass spectrometer (PTR-MS) to measure volatile organic compounds (VOCs).
These projects are currently supported by several major research grants from NSF, NOAA, and Ohio Board Regents (OBR).
1. Kinetics Studies of Aerosol Nucleation: Laboratory Studies
We study chemical processes of nucleation under atmospherically relevant conditions, with two high-sensitivity CIMS to directly measure low concentrations of aerosol precursors (sulfuric acid, ammonia and organic compounds). Our objectives are to investigate the role of ammonia and organic compounds that play in aerosol nucleation and growth. These results will provide information of immediate use to modelers who are trying to predict aerosol and cloud condensation nuclei concentrations.
2. Atmospheric Observations of New Particle Formation
2.1. Long-term observations of new particle formation: In the relatively less polluted atmosphere (Kent, Ohio)
We have been conducting long-term, ground-based observations of new particle formation at Kent, OH, by directly measuring sulfuric acid and ammonia with CIMS (starting from January 2006). Using this unique and rich datasets of aerosol sizes and aerosol precursors, we investigate aerosol nucleation processes in the lower troposphere.
We perform field studies of new particle formation, by measuring aerosol precursors (sulfuric acid, ammonia, and amines) and aerosol sizes under various atmospheric conditions, including mixed forests and coastal regions.
Please click here to see our recent field studies.