Lin, Yue Bahreini, Roya Zimmerman, Stephen Fofie, Emmanuel A. Asa-Awuku, Akua Park, Kihong Lee, Seung-Bok Bae, Gwi-Nam Jung, Heejung S. 2024-01-19T22:03:51Z 2024-01-19T22:03:51Z 2021-09-03 2018-08 1352-2310 https://pubs.kist.re.kr/handle/201004/121094 Size-resolved effective densities of ambient aerosols in Riverside, CA were determined over 4 periods during 2015-2016. A DMA-CPMA-CPC technique was used to measure effective density for particles with selected diameters of 50, 70, 101 and 152 nm. A catalytic stripper (CS) was used alternately to remove the volatile fraction of aerosol before density measurements. Aerosol non-refractory composition measurement was conducted in June 2016 campaign to understand the effect of chemical composition on particle density. The average densities for particles over all the measurement campaigns over BP mode (i.e. bypassing the CS) were 1.17 g/cm(3) at 50 nm and L25-1.28 g/cm(3) at 70, 101 and 152 nm. The average density after CS conditioning (CS mode) showed a decreasing trend from 1.22 g/cm(3) to 1.04 g/cm(3), with increase in the selected size, and a mass fractal dimension (D-f) of 2.85. Both the BP and CS mode particles showed the lowest effective density at 6-9 am and highest density at 11 a.m.-3 pm. The diurnal variation of density for both modes became more intensive as particle size increased. The variation was also more intense for the CS mode compared to the BP mode. Organic aerosol and ammonium nitrate mass in the size range of density measurements correlated well positively (R-2 = 0.78) and negatively (R-2 = 0.62), respectively with BP mode effective density. The study provides an update to the aerosol density profiles of a well-known receptor site (Riverside, CA) and investigates the transformation of particles in different seasons. The effective density profiles will be used in a follow-up study to better estimate the respiratory-deposited ambient aerosol mass. English PERGAMON-ELSEVIER SCIENCE LTD PARTICLE MASS MOBILITY SPECTROMETER CLASSIFICATION Investigation of ambient aerosol effective density with and without using a catalytic stripper Article 10.1016/j.atmosenv.2018.05.063 1 ATMOSPHERIC ENVIRONMENT, v.187, pp.84 - 92 ATMOSPHERIC ENVIRONMENT 187 84 92 scie scopus 000439672800008 2-s2.0-85047728761 Environmental Sciences Meteorology & Atmospheric Sciences Environmental Sciences & Ecology Meteorology & Atmospheric Sciences Article PARTICLE MASS MOBILITY SPECTROMETER CLASSIFICATION Riverside Secondary organic aerosol Effective density Catalytic stripper Thermal denuder Receptor