Characterization of aerosol size distributions and chemical compositions under strong wind and stagnant conditions during haze episodes in Lin ’an, China

AbstractA long-lasting haze episode which included a strong wind pollution day (SWPD) and stable pollution days (SPD) occurred in Lin ’an from January 21 to 26, 2015. On Jan. 21, the Lin’an atmospheric background station experienced a north wind at ground level, which resulted in short-term northern input–based pollution. During January 23 to 26, stable atmospheric conditions led to a local accumulation of pollutants. The av erage number concentration, surface area concentration, volume concentration, and concentration of PM2.5 were 14,183  ± 7121 cm−3, 576  ± 154 μm2 cm−3, 1009  ± 151 μm3 cm−3, and 145  ± 41 μg/m3 in SWPD; 14,497  ± 7418 cm−3, 1033  ± 241 μm2 cm−3, 1435  ± 540 μm3 cm−3, and 205  ± 44 μg/m3 in SPD. The extinction coefficients calculated in SWPD and SPD were 523.7  ± 281.7 Mm−1 and 918.0  ± 416.9 Mm−1. The number concentration spectra in SWPD were a bimodal distribution, which exhibited peak values at 38  nm and 88 nm (11,422 cm−3 nm−1 and 11,043  cm−3 nm−1). The number concentration spectra in SPD were a unimodal distribution with a peak at 96  nm (15,375 cm−3nm−1). Surface concentration spectra in SWPD and SPD were three-peak distributions with maximum concentration peaks at 230  nm and 575 nm (808 μm2 cm−3 nm−1 and 1087  μm2 cm−3 nm−1), respectively. The volume concentration spectra of SWPD had a four-peak distribution with peaks...
Source: Air Quality, Atmosphere and Health - Category: Environmental Health Source Type: research