Using the visibility data during 2010 to 2012 obtained at Shenyang Atmosphere Observation Center, the relationships between visibility, PM mass concentration and meteorological elements were statistically analyzed. Th...
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Using the visibility data during 2010 to 2012 obtained at Shenyang Atmosphere Observation Center, the relationships between visibility, PM mass concentration and meteorological elements were statistically analyzed. The results show that: The monthly averaged visibility over Shenyang is higher in March and September with values about 19.0±4.3km and 17.1±4.3km, respectively. Low visibilities over Shenyang occur in January about 11.0±4.7km. Among the meteorological elements, wind speed was the main meteorological factor that influenced visibility and the PM mass concentrations. The number of days with visibility >19.0 km and visibility <10.0 km in Shenyang are 59, 123, 145 and 132, 119, 121 from 2010 to 2012. The relationship between visibility and PM indicated that human activities are already main sources of the pollutants, especially the fine particles which is the most important factor for the deterioration of visibility. The study shows an obvious diurnal variation and weekend effect of visibility and PM which are mainly due to human activities.
Ambient daytime and nighttime PM2.5 and TSP samples were collected in parallel at two sites(named Pudong and Jinshan) in Shanghai, China. The samples were analyzed for carbon fractions, elements, water-soluble ions(WS...
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Ambient daytime and nighttime PM2.5 and TSP samples were collected in parallel at two sites(named Pudong and Jinshan) in Shanghai, China. The samples were analyzed for carbon fractions, elements, water-soluble ions(WSIs) at both sites. The lower concentrations of particulates were found at Pudong, and higher level of PM2.5 and TSP concentrations were observed in daytime than nighttime for both sites. The variations of chemical components(OC, EC, ions and elements) as well as the species ratios were discussed in depth for daytime and nighttime. The results showed that organic aerosol and secondary sulfate are the most abundant components of the particle, and the contributions were variable during the different sampling periods due to the strength of local emission and the secondary production. The discussion indicated that the particulates were variable for different areas according to the local emissions and meteorology. The results can give some indications for the developing effective strategies for urban sub-zone pollution control.
With an Aerodyne Aerosol Chemical Speciation Monitor, we mainly focused on the variation of NRM1 species, its inorganic species formation and its effect on visibility impairment under a stable atmospheric condition(l...
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With an Aerodyne Aerosol Chemical Speciation Monitor, we mainly focused on the variation of NRM1 species, its inorganic species formation and its effect on visibility impairment under a stable atmospheric condition(low wind speed period, from 1 September to 6 September, from 26 September to 1 October respectively). The NRM1 took up 0% of PM2.5. Organic contributes the most(58% on average) to the NRM1 mass loading, other species make 0% contributions. Through Principle component analysis, we found NH4+, SO42- and NO3- played a stably significant role on visibility impairment within different period of the day. With the IMPROVE equation, Light scattering from NRM1 was ~ 80% of that from PM2.5, illustrating the dominance of NRM1 in the light scattering process. Organics contributed the most to light scattering during this period whereas(NH4)2SO4 and NH4NO3 played more important role on the visibility variation than Org did. Overall, it is the combination of organics,(NH4)2SO4 and NH4NO3, not a single species that are responsible for the variation of visibility variation. Sulfate formation was dominated with gas phase reactions during daytime and droplet phase reactions at night. Nitrate particles, however, were not formed immediately after gas phase reactions in the afternoon. Two types of OA(HOA and OOA) were found in this study. The oxygenation level of organics was relatively high and photochemical reaction proceeded rapidly in the afternoon. BBOA(biomass burning organic aerosol) cannot be resolved though tracers of BBOA(m/z 60 and 73) have a prominent signal, illustrating the similar variation of time series between these two factors, which maybe resulted from the traditional energy consumption pattern in villages.
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