HR: 08:00h
AN: A41E-01    [Abstracts]
TI: Comparison of temporal variations in fine carbonaceous particles at rural and urban sites in Canada and China
AU: * Yang, F
EM: fumo.yang@ec.gc.ca
AF: Environment Canada, 4905 Dufferin Street, Toronto, ON M3H 5T4, Canada
AU: * Yang, F
EM: fumo.yang@ec.gc.ca
AF: Graduate University of Chinese Academy of Sciences, 19(Jia) Yuquanlu, Shijingshan, Beijing, 100049, China
AU: Huang, L
EM: lin.huang@ec.gc.ca
AF: Environment Canada, 4905 Dufferin Street, Toronto, ON M3H 5T4, Canada
AU: Sharma, S
EM: sangeeta.sharma@ec.gc.ca
AF: Environment Canada, 4905 Dufferin Street, Toronto, ON M3H 5T4, Canada
AU: He, K
EM: hekb@tsinghua.edu.cn
AF: Tsinghua University, 1 Tsinghuayuan, Haidian, Beijing, 100084, China
AU: Brook, J
EM: jeff.brook@ec.gc.ca
AF: Environment Canada, 4905 Dufferin Street, Toronto, ON M3H 5T4, Canada
AU: Jia, Y
EM: jiayingtao99@mails.tsinghua.edu.cn
AF: Tsinghua University, 1 Tsinghuayuan, Haidian, Beijing, 100084, China
AU: Gao, S
EM: shidong.gao@ec.gc.ca
AF: Environment Canada, 4905 Dufferin Street, Toronto, ON M3H 5T4, Canada
AU: Zhao, Q
EM: zhaoq@mails.tsinghua.edu.cn
AF: Tsinghua University, 1 Tsinghuayuan, Haidian, Beijing, 100084, China
AB: Weekly and/or daily PM2.5 samples were collected at a rural site (i.e. Egbert, Ontario, about 80 km Northwest of Toronto, 43°41'N, 79°38'W) since August 2005 and an urban site (i.e. Downsview, Toronto) in Canada since October 2006. Similar collections were simultaneously conducted at a rural site (Miyun, about 100 km Northeast of Beijing, 39°54'N, 116°25'E) and an urban site (i.e. Tsinghua) around Beijing area in China, for two consecutive years (2005 and 2006). In order to characterize the temporal variation (e.g. seasonal changes) of carbonaceous components in ambient PM of big cities, understanding the their impacts on the background levels of PM and identify possible sources and their attributions, individual carbon fractions, i.e. organic carbon (OC) and elemental carbon/black carbon (EC/BC) were measured for these samples from a paired urban-rural sites in both Canada and China. The results show that: A). in Egbert, weekly concentrations varied a lot ranging from 0.3 to 3.1 μg m^-3 in OC and from 0.05 to 1.8 μg m^-3 in EC with an average of 1.7±0.9 μg m^-3 and 0.6±0.3 μg m^-3, respectively. OC and EC concentrations were 80% and 50% higher during summertime than during wintertime. Typical episodes related to high variations in OC and EC concentrations during both warm and cold seasons corresponded well to southern-northern wind directions, implying the impact of urban sources from the south. B). In Beijing, an average concentrations at the rural site was 14.4±6.8 μg m^-3 in OC and 3.5±2.1 μg m^-3 in EC, a factor of 7.5 and 4.8 higher than those at the rural site in Canada, respectively, whereas those at the urban site were even higher by another factor of 0.6 and 1.2 than their corresponding values at the rural site, respectively. In contrast to the seasonal pattern at Egbert, Canada, the average concentrations of both OC and EC were much higher during winter season than those during summer by a factor of 0.6-1.2, respectively. It was likely due to enhanced emissions from coal combustions for space heating coupled with some specific meteorological conditions (e.g. low wind speed, low mixing height and high relative humidity etc.). Stable isotope measurements of individual carbon fractions in both ambient and source PM2.5 are likely to provide additional constraints on source identifications and attributions for ambient carbonaceous PM, including the impacts from local emissions and long-range transport.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0345 Pollution: urban and regional (0305, 0478, 4251)
DE: 0478 Pollution: urban, regional and global (0345, 4251)
SC: Atmospheric Sciences [A]
MN: 2007 Joint Assembly