期刊
ATMOSPHERIC ENVIRONMENT
卷 173, 期 -, 页码 239-247出版社
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.atmosenv.2017.11.013
关键词
Size-segregated aerosols; Organic carbon; WSOC; HULIS; Levoglucosan; Biomass burning
资金
- European Union Seventh Framework Programme (FP7) Marie Curie FP7-PEOPLE-COFUND through NEWFELPRO project [291823, 47]
- Slovenian Research Agency [P1-0034-0140]
Long-term measurements of carbon in HUmic-LIke Substances (HULLS-C) of ambient size-segregated water soluble organic aerosols were performed using a ten-stage low-pressure Berner impactor from December 2014 to November 2015 at an urban background environment in Ljubljana, Slovenia. The mass size distribution patterns of measured species (PM - particulate matter, WSOC - water-soluble organic carbon and HULLS-C) for all seasons were generally tri-modal (primarily accumulation mode) but with significant seasonal variability. HULLS-C was found to have similar distributions as WSOC, with nearly the same mass median aerodynamic diameters (MMADs), except for winter when the HULLS-C size distribution was bimodal. In autumn and winter, the dominant accumulation mode with MMAD at ca. 0.65 mu m contributed 83 and 97% to the total HULLS-C concentration, respectively. HULIS-C accounted for a large fraction of WSOC, averaging more than 50% in autumn and 40% in winter. Alternatively, during warmer periods the contributions of ultrafine (27% in summer) and coarse mode (27% in spring) were also substantial. Based on mass size distribution characteristics, HULIS-C was found to be of various sources. In colder seasons, wood burning was confirmed as the most important HLTLIS source; secondary formation in atmospheric liquid water also contributed significantly, as revealed by the MMADs of the accumulation mode shifting to larger sizes. The distinct difference between the spring and summer ratios of HULIS-C/WSOC in fine particles (ca. 50% in spring, but only 10% in summer) indicated different sources and chemical composition of WSOC in summer (e.g., SOA formation from biogenic volatile organic compounds (BVOCs) via photochemistry). The enlarged amount of HULLS-C in the ultrafine mode in summer suggests that the important contribution was most likely from new particle formation during higher emissions of BVOC due to the vicinity of a mixed deciduous forest; the higher contribution of HULLS-C in the coarse mode demonstrated that beside soil erosion other sources, such as pollen and plant fragments, could also be responsible.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据