Insitu measurements of laser-induced-fluorescence spectra of single atmospheric organic carbon aerosol particles for their partial classification. (Invited)
Abstract
Aerosols are ubiquitous in the earth’s atmosphere. Within the last two decades, the importance of organic carbon aerosols (OCAs) has been widely recognized. OCAs have both natural and anthropogenic sources and have effects ranging from atmospheric radiative forcing to human health. Improved methods for measuring and classifying OCAs are needed for better understanding their sources, transformation, and fate. In this talk we focus on the use of a relatively new technique for characterization of single OCA particles in atmospheric aerosol: ultraviolet laser-induced-fluorescence (UV-LIF). UV-LIF spectra of atmospheric aerosols measured at multiple sites with different regional climate (Adelphi, MD, New Haven, CT, and Las Cruces, NM) are reported. A hierarchical clustering method was used to cluster (approximately 90%) of the single-particle UV-LIF spectra into 8-10 groups (clusters). Some of these clusters have spectra that are similar to spectra of some important classes of atmospheric aerosol, such as humic/fulvic acids and humic-like substances, bacteria, cellulose, marine aerosol, and polycyclic aromatic hydrocarbons. The most highly populated clusters, and some of the less populated ones, appear at all sites. On average, spectra characteristic of humic/fulvic acids and humic-like-substances (HULIS) comprise 28-43% of fluorescent particles at all three sites; whereas cellulose-like spectra contribute only 1-3%.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2009
- Bibcode:
- 2009AGUFM.B31D..07P
- Keywords:
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- 0305 ATMOSPHERIC COMPOSITION AND STRUCTURE / Aerosols and particles;
- 0422 BIOGEOSCIENCES / Bio-optics;
- 0452 BIOGEOSCIENCES / Instruments and techniques