Understanding atmospheric aerosols is important to understanding the effects of aerosols 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 initial step in the chain reactions that lead to cloud formation, but the nucleation 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 the art chemical and aerosol instruments,
including two Chemical Ionization Mass Spectrometers (CIMS)
that measure low concentrations of sulfuric acid, ammonia and amines; three
Scanning Mobility Particle Spectrometers (SMPS); and a particle size magnifier (PSM, Airmodus) which measures sub-3 nm particles and clusters.
We also have a proton transfer mass spectrometer (PTR-MS) that measures various volatile organic compounds (VOCs).
These projects have been supported by several 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, amines and organic compounds). Our objective is to investigate the role that ammonia and organic compounds
play in aerosol nucleation and growth.
2. Atmospheric Observations of New Particle Formation
We have been conducting long-term, ground-based observations of new particle formation at Kent, Ohio. This site is one of the few sites in the U.S. where long-term measurements of
aerosol size distributions were conducted (from 2006 to present). Sulfuric acid, ammonia and amines were also measured from 2009. We also performed field studies of new particle formation in Pellston, Michigan; Ozark, Missouri; Brookhaven, New York; Centerville, Alabama. Please click here to
see the field studies we have participated.
3. Atmospheric Observations of Amines
We have developed a new chemical ionization mass spectrometer (CIMS) that can measure ambient amines at the ppt or sub-ppt level with a fast time response (less than 1 minute).
With this amine-CIMS, we conducted amine measurements in Kent, Ohio and Centerville, Alabama.
4. Measurements of Henry's Law Constants of Organic Compounds
We measure solubililty of various volatile organic compounds (VOCs) with GC-FID.
***All observation data from the above projects are available to anyone. Please contact Shanhu Lee (email@example.com) to request for sharing data.***