Secondary formation of organic aerosol in the Los Angeles Basin. Investigation of the diurnal variations of organic and elemental carbon

A data base of time-resolved, particulate organic and elemental carbon values now exists for an extended period of summer and fall days during which supporting measurements are abundant. This information should prove useful for analyzing organic aerosol chemistry in the Los Angeles Basin with appropriate time resolved advection-diffusion-chemical reaction models. Preliminary examination of the in situ analyzer data for organic and elemental carbon has shown the existence of summer days on which the correlation between OC and EC is quite high, indicating a primary origin for the organic aerosol. It has also identified three multiple day episodes during which secondary formation contributed significantly to organic aerosol concentrations.