scholarly journals 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)

2018 ◽  
Vol 123 (18) ◽  
Author(s):  
Chia‐Li Chen ◽  
Sijie Chen ◽  
Lynn M. Russell ◽  
Jun Liu ◽  
Derek J. Price ◽  
...  
Keyword(s):  
Aerosol Particle ◽  
Chemical Properties ◽  
Organic Aerosol ◽  
San Joaquin Valley ◽  
South Coast ◽  
South Coast Air Basin

scholarly journals Fine-scale simulation of ammonium and nitrate over the South Coast Air Basin and San Joaquin Valley of California during CalNex-2010

2014 ◽  
Vol 119 (6) ◽  
pp. 3600-3614 ◽  
Author(s):  
James T. Kelly ◽  
Kirk R. Baker ◽  
John B. Nowak ◽  
Jennifer G. Murphy ◽  
Milos Z. Markovic ◽  
...  
Keyword(s):  
San Joaquin Valley ◽  
South Coast ◽  
Fine Scale ◽  
The South ◽  
South Coast Air Basin

scholarly journals Contribution of Water to Particulate Mass in the South Coast Air Basin

1995 ◽  
Vol 22 (1) ◽  
pp. 111-123 ◽  
Author(s):  
Zhaoyue Meng ◽  
John H. Seinfeld ◽  
Pradeep Saxena ◽  
Yong Pyo Kim
Keyword(s):  
South Coast ◽  
The South ◽  
Particulate Mass ◽  
South Coast Air Basin

scholarly journals Relating hygroscopicity and optical properties to chemical composition and structure of secondary organic aerosol particles generated from the ozonolysis of α-pinene

2014 ◽  
Vol 14 (7) ◽  
pp. 10543-10596 ◽  
Author(s):  
C. Denjean ◽  
P. Formenti ◽  
B. Picquet-Varrault ◽  
E. Pangui ◽  
P. Zapf ◽  
...  
Keyword(s):  
Optical Properties ◽  
Secondary Organic Aerosol ◽  
Complex Refractive Index ◽  
Glassy State ◽  
Particle Surface ◽  
Chemical Properties ◽  
Organic Aerosol ◽  
Atomic Ratio ◽  
Scattering Coefficient ◽  
Size Growth

Abstract. Secondary Organic Aerosol (SOA) were generated from the ozonolysis of α-pinene in the CESAM simulation chamber. The formation and ageing of the SOA were studied by following their optical, hygroscopic and chemical properties. The optical properties investigated by determining the particle Complex Refractive Index (CRI). The hygroscopicity was quantified by measuring the effect of RH on particle size (Growth Factor, GF) and scattering coefficient (f(RH)). The oxygen to carbon (O : C) atomic ratio of the particle surface and bulk were used as a sensitive parameter to correlate the changes in hygroscopic and optical properties of the SOA composition in CESAM. The real CRI at 525 nm wavelength decreased from 1.43–1.60 (±0.02) to 1.32–1.38 (±0.02) during the SOA formation. The decrease in real CRI correlates with a decrease in the O : C ratio of SOA from 0.68 (±0.20) to 0.55 (±0.16). In contrast, the GF stayed roughly constant over the reaction time, with values of 1.02–1.07 (±0.02) at 90% (±4.2) RH. Simultaneous measurements of O : C ratio of the particle surface revealed that the SOA was not composed of a homogeneous mixture, but with less oxidised species at the surface which would limit the water adsorption onto particle. In addition, an apparent change of both mobility diameter and scattering coefficient with increasing RH from 0 to 30% was observed for SOA after 16 h reaction. We postulate that this change could be due to a change in the viscosity of the SOA from a predominantly glassy state to a predominantly liquid state.

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