Organic Aerosol Particle Chemical Properties Associated With Residential Burning and Fog in Wintertime San Joaquin Valley (Fresno) and With Vehicle and Firework Emissions in Summertime South Coast Air Basin (Fontana)

Abstract

Organic aerosol mass (OM) components were investigated at Fresno in winter and at Fontana in summer by positive matrix factorization of high‐resolution time‐of‐flight aerosol mass spectra and of Fourier Transform infrared spectra, as well as by k‐means clustering of light‐scattering (LS) aerosol single‐particle spectra. The results were comparable for all three methods at both sites, showing different contributions of primary and secondary organic aerosol sources to PM1. At Fresno biomass burning organic aerosol contributed 27% of OM on low‐fog days, and nitrate‐related oxidized OA (NOOA) accounted for 47% of OM on high‐fog days, whereas at Fontana very oxygenated organic aerosol (VOOA) components contributed 58–69% of OM. Amine and organosulfate fragment concentrations were between 2 and 3 times higher on high‐fog days than on low‐fog days at Fresno, indicating increased formation from fog‐related processes. NOOA and biomass burning organic aerosol components were largely on different particles than the VOOA components in Fresno, but in Fontana both NOOA and VOOA components were distributed on most particle types, consistent with a longer time for and a larger contribution from gas‐phase photochemical secondary organic aerosol formation in summer Fontana than winter Fresno. Uncommon trace organic fragments, elevated inorganic, and alcohol group submicron mass concentrations persisted at Fontana for more than 5 days after 4 July fireworks. These unique aerosol chemical compositions at Fresno and Fontana show substantial and extended air‐quality impacts from residential burning and fireworks.

Light Absorption by Ambient Black and Brown Carbon and its Dependence on Black Carbon Coating State for Two California, USA, Cities in Winter and Summer

“…The OA composition data were further analyzed using positive matrix factorization (PMF; Zhang, Jimenez, et al, ). Four OA factors were determined during the Fresno campaign, identified as biomass burning OA (BBOA), hydrocarbon‐like OA (HOA), and two types of oxygenated OA identified as a very oxygenated OA (VOOA) type and a nitrate‐associated OA (NOOA) type (Chen et al, ). For Fontana, four OA factors were also determined and identified as hydrocarbon‐like OA (HOA), cooking‐related OA (COA), and two oxygenated OA factors, referred to here as a more‐oxidized very oxidized OA (VOOA) and a less‐oxidized, NOOA type (Chen et al, ).…”

“…Fontana is located inland in the South Coast Air Basin that includes the megacity Los Angeles. Measurements of ensemble‐average particle composition are presented in Chen et al (), and BC‐containing particle composition and mixing state are discussed in Lee et al (). The South Coast Air Basin is a highly photochemically active environment in the summertime, with much of the particulate matter being secondary in origin (Docherty et al, ; Hayes et al, ), especially material that is internally mixed with BC (Cappa et al, ; Lee et al, ).…”

Formation of secondary organic aerosol coating on black carbon particles near vehicular emissions

“…Canagaratna Chen et al, 2018) in order to perform a more meaningful comparison to our SP-AMS measurements in the Van Krevelen diagram (Fig. 7).…”

“…5i). Chen et al (2018) identified four PMF factors, namely HOA, cooking OA (COA), nitrate-related OOA (NOOA), and very oxygenated OA (VOOA), to describe the potential sources of OA measured with the HR-ToF-AMS (Fig. S6) in this field campaign.…”

“…2.2 and 2.3 for the descriptions of the SP-AMS and the calibration approach, respectively). The details of other particle instruments, including a HR-ToF-AMS (Aerodyne Research), a single-particle soot photometer (SP2, Droplet Measurement Technologies), and a scanning electrical mobility spectrometer (SEMS, Brechtel), have been reported in Chen et al (2018) and Betha et al (2018). Two nitrogen oxide analyzers (model 42i and 42i NO y , Thermo Fisher Scientific) were used to measure mixing ratios of NO x and NO y for determining photochemical age (PCA) of air masses.…”