Advanced IMPROVE Studies
EMSL Project ID
43591
Abstract
This EMSL proposal will contribute to ongoing research sponsored by EPRI to elucidate aerosol chemical and physical properties which contribute to haze in U.S. national parks. This research tests various assumptions underlying the "IMPROVE" equation which is used to estimate aerosol light extinction for compliance under the U.S. EPA's Regional Haze Rule. The primary issues include: 1) the relationship between chemically resolved size distribution and mass scattering efficiencies; 2) the chemical composition of aerosol organics; 3) hygroscopic growth by water soluble organics; and 4) determination of the ambient hygroscopic state as it relates to deliquescence and hysteresis. The proposed collaboration with Dr. Lizabeth Alexander of PNNL will enable continuous measurement of size-resolved aerosol chemical composition using the EMSL high resolution time-of-flight Aerosol Mass Spectrometer (H-ToF AMS) and proton transfer reaction mass spectrometer (PTR-MS) at Acadia National Park during July and August, 2011. A similar experiment was conducted at Mt. Rainier National Park in August, 2009 under EMSL project #36409. The aerosol at Mt. Rainier was dominated by organics. Aerosol at Acadia is comprised of similar proportions of aged, transported sulfates and secondary organics. The EMSL AMS will provide real-time measurements of the organic mass to organic carbon (OCM/OC) ratio and the relationship between particle size and chemical concentration, both of which are important components of the IMPROVE equation. Characterization of ambient organic aerosols using the EMSL AMS and VOC's using the PTR-MS will provide information on organic composition, for example, oxygenated and hydrocarbon-like organic aerosols (OOA and HOA), and its relationship to hygroscopic growth. The deployment of the EMSL AMS and PTR-MS during the Acadia field campaign will provide invaluable information on aerosol composition and size at relatively low cost. This project has direct implications for national policy on air pollution mitigation at remote national parks.
Project Details
Project type
Exploratory Research
Start Date
2011-06-01
End Date
2012-06-03
Status
Closed
Released Data Link
Team
Principal Investigator