Characteristics of aerosols and mass closure study at two WMO GAW regional background stations in eastern China

The Concentrations, Formations, Relationships and Modeling of Sulfate, Nitrate and Ammonium (SNA) Aerosols over China

“…Notably, the fractions of nitrate in PM 2.5 and PM 10 are comparable. Considering that the mass concentration of PM 10 is higher than that of PM 2.5 (175.28 ± 118.94 µg m -3 vs. 99.63 ± 54.69 µg m -3 in Tables S2 and S1), this signifies that nitrate in coarse particles has a certain contribution to PM 10 mass and can't be ignored Yan et al, 2012), which is consistent with the results from Putaud et al (2004) in Europe. Compared to those in USA (49.2%) (Hand et al, 2011) and Europe (38.7%) (Sillanpää et al, 2006), the total SNA fraction in fine particle in China is lower (Figs.…”

“…Sulfate, nitrate and ammonium (abbreviated as SNA) are the dominant secondary species of aerosols (~30-50% in PM 2.5 ). They can determine the chemical characteristic of particle by changing particles' hygroscopicity and acidity, influence the optical properties of particles and the earth's radiation balance by scattering and absorbing solar radiation, change cloud nucleation process by acting as cloud condensation nuclei (CCN) and then affect climate, and the most important, penetrate deeply to human lung and deteriorate human health (Xu et al, 2002;Sun et al, 2004;Cheung et al, 2005;Hu et al, 2008;Pathak et al, 2009;Cheng et al, 2011;Sang et al, 2011;Gao et al, 2012;Yan et al, 2012).…”

Chemical characterization of size-resolved aerosols in four seasons and hazy days in the megacity Beijing of China

“…4 shows the chemical components of size-resolved particles in the four seasons. In fine particles, OM and SIA accounted for more than half of the particle mass in each size bin, which indicated that secondary processes significantly contributed to the heavy particle pollution in Beijing (He et al, 2001;Sun et al, 2004;Yan et al, 2012;Huang et al, 2010;Li et al, 2012). In addition, OM and SIA fractions increased with decreasing particle size, from 68.1% in 1-1.8 μm to 90% in 0.18-0.32 μm ranges, which indicated that particles of small size would exert more serious environmental impacts.…”

Impacts of aerosol chemical compositions on optical properties in urban Beijing, China

“…The optical properties of aerosols are considered to be related to their chemical compositions and particle size distributions (Bergin et al, 2001). To date, most studies have focused on analyzing the mass concentration, size distribution, and different chemical species in ambient air in China (Yan et al, 2012;Zhang, Cao, Lee, Shen, & Ho, 2007). As a recent example, Zhang et al (2013) explored in detail the seasonal variation of the chemical species, including organic carbon (OC), elemental carbon (EC), ions, and elements of PM 2.5 .…”