| 1 | Vertical distribution of aerosol optical properties based on aircraft measurements over the Loess Plateau in China显示文摘Vertical distributions of aerosol optical properties based on aircraft measurements over the Loess Plateau were measured for the first time during a summertime aircraft campaign, 2013 in Shanxi, China. Data from four flights were analyzed. The vertical distributions of aerosol optical properties including aerosol scattering coefficients(σsc), absorption coefficients(σab),Angstr?m exponent(α), single scattering albedo(ω), backscattering ratio(βsc), aerosol mass scattering proficiency(Q sc) and aerosol surface scattering proficiency(Q sc′) were obtained. The mean statistical values of σsc were 77.45 Mm-1(at 450 nm), 50.72 Mm-1(at 550 nm), and32.02 Mm-1(at 700 nm). The mean value of σab was 7.62 Mm-1(at 550 nm). The mean values ofα, βsc and ω were 1.93, 0.15, and 0.91, respectively. Aerosol concentration decreased with altitude. Most effective diameters(ED) of aerosols were less than 0.8 μm. The vertical profiles of σsc,, α, βsc, Q sc and Q sc′ showed that the aerosol scattering properties at lower levels contributed the most to the total aerosol radiative forcing. Both α and βsc had relatively large values, suggesting that most aerosols in the observational region were small particles. The mean values of σsc, α, βsc, Q sc, Q sc′, σab and ω at different height ranges showed that most of the parameters decreased with altitude. The forty-eight hour backward trajectories of air masses during the observation days indicated that the majority of aerosols in the lower level contributed the most to the total aerosol loading, and most of these particles originated from local or regional pollution emissions. | Junxia Li Xingang Liu Liang Yuan Yan Yin Zhanqing Li Peiren Li Gang Ren Lijun Jin Runjun Li Zipeng Dong Yiyu Li Junmei Yang | 2015 | Journal of Environmental Sciences2015，27，8： | 6 |
| 2 | Effect of short-term regional traffic restriction on urban submicron particulate pollution显示文摘During the 2013 and 2015 Lanzhou International Marathon Events(LIME1 and LIME2),the local government made a significant effort to improve traffic conditions and air quality by implementing traffic restriction measures. To fill the gap in information on the effect of short-period(several hours)traffic control on urban air quality,submicron particle size distributions and meteorological data were measured simultaneously during June 2013 and June 2015 in urban Lanzhou. The number and surface area concentrations of particles in the100–200 nm range declined by 67.2% and 65.0% for LIME1 due to traffic control,while they decreased by 39.2% and 37.1% for LIME2. The impact of traffic restriction on air pollution near the sampling site lagged behind the traffic control period for LIME2. In addition,the effect of traffic restriction on air pollution near the sampling site was dependent on the distance between the relative orientation of the sampling site and traffic-restricted zones,as well as meteorological conditions such as wind direction. The influence of traffic restrictions on the particle concentrations differed for different particle sizes. The size range most affected by traffic restriction was 60–200 and 60–300 nm for number and surface area concentrations in the urban environment,respectively,while for the particle volume concentration it was the 100–600 nm range. This study will provide a basis for implementation of future urban traffic-induced particulate pollution control measures. | Suping Zhao Ye Yu | 2017 | Journal of Environmental Sciences2017，29，5： | 0 |
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