Code 613.2 Branch Seminar Series: Judith C. Chow, John G. Watson and Mark C. Green

Desert Research Institute, Reno, Nevada

This presentation describes PM2.5 networks, measurement methods, and data bases, examines the validity of assumptions for space-based estimates of surface PM2.5 measurements, and identifies opportunities for collaboration among air quality and space scientists. Surface-based PM is measured long-term for National Ambient Air Quality Standards (NAAQS) compliance, visibility progress, and research studies. Major long-term networks are National Air Monitoring Stations (NAMS)/State or Local Air Monitoring Stations (SLAMS), Chemical Speciation Network (CSN; including the Speciation Trends Network [STN]), Interagency Monitoring of PROtected Visual Environments (IMPROVE), and Southeastern Aerosol Research and Characterization (SEARCH). PM2.5 is measured by 24-hour filter samples, inertial microbalances, and beta attenuation monitors. Federal Reference Methods (FRMs), Federal Equivalent Methods (FEMs), and speciation samplers do not provide equivalent PM2.5 mass under all circumstances. Major chemical components are measured to attain mass closure and determine emission reduction needs. Organic and elemental carbon have been inconsistently measured and have large uncertainties. PM data are available in web-based formats, but the validity of assumptions for surface/satellite PM comparisons can be evaluated from supersite measurements.

About Our Speaker
Dr. Chow is engaged in developing and applying advanced analytical methods to characterize suspended atmospheric particles for source attribution and their effects on visibility and health. She has been actively involved in the development of EC/OC analyzing protocol, and California’s Fresno Supersite study, among many other major scientific projects.