The mass of light absorbing carbon (LAC) in individual, internally mixed aerosol particles was measured with the Single Particle Soot Photometer (SP2) in April of 2003 and 2005 and evaluated with respect to concentrations of carbon monoxide (CO), particle bound polycyclic aromatic hydrocarbons (PPAH) and condensation nuclei (CN). The LAC and CO have matching diurnal trends that are linked to traffic patterns and boundary layer growth.

- D. Baumgardner1, G. L. Kok2, and G. B. Raga1