AAAR 34th Annual Conference
October 12 - October 16, 2015
Hyatt Regency
Minneapolis, Minnesota, USA
Abstract View
Observed and Modeled Particle Size Distributions at Rural and Urban New York Sites
JAMES SCHWAB, G. Garland Lala, Fangqun Yu, H. Dirk Felton, Oliver Rattigan, University at Albany, SUNY
Abstract Number: 231 Working Group: Remote and Regional Atmospheric Aerosols
Abstract For six months in 2012 we measured particle number concentrations and size distributions at two locations in New York State separated by a little over 300 km. The sites are Pinnacle State Park in Addison, NY in southwestern upstate New York, and Queens College in the borough of Queens, New York City. Relevant measurements at the Addison site consisted of paired nano- and long-tube SMPS systems to cover the size range from 5 to ~700 nm mobility size, an Aerodynamic Particle Sizer for the range 0.3 -20 µm, and a 3783 water-based Environmental Particle Counter (EPC) for concentrations of particles greater than 7 nm diameter. At the Queens College site the size distributions were measured with a Fast Mobility Particle Sizer, an Optical Particle Sizer (TSI Model 3330) for part of the period, and an identical 3783 EPC. Simultaneous measurements at the two sites were carried from April through September 2012.
Observed particle size distributions and number concentrations are analyzed to identify new particle formation and growth events, and other phenomena influencing these measurements at the two sites. Additionally, model simulations showing PSDs and CN concentrations are presented and compared for the PSP site using the GEOS-Chem plus APM (Advanced Particle Microphysics) modeling tools.
Measurements and simulations at PSP both show frequent new particle formation (NPF) and growth events in April, and very few in the summer months of July and August. Overall, there appear to be more simulated than observed NPF events. The GEOS-Chem grid spacing is too coarse to adequately capture particle dynamics at the New York City site, but other tools (including recently available GEOS-Chem/APM nested grid simulations at 0.25 degrees x 0.3125 degrees horizontal resolution) will be investigated to see if they are up to the task.