Size Resolved Aerosol OC, EC at a Regional Background Station in the Suburb of Beijing
-
摘要: 利用北京上甸子区域大气本底站2004年观测的分粒径大气气溶胶资料,分析了气溶胶中有机碳 (OC) 及元素碳 (EC) 的质量浓度水平、季节变化、尺度分布特征、OC与EC比值及其相关性。结果显示:上甸子站总悬浮颗粒物 (TSP) 中OC平均质量浓度为7.5~31.5 μg·m-3,EC质量浓度为1.4~6.6 μg·m-3;PM2.1(粒径小于2.1 μm) 中OC质量浓度为4.0~19.1 μg·m-3,EC质量浓度大约为0.8~4.3 μg·m-3。冬季OC及EC质量浓度明显高于其他季节,其中冬、夏、秋季OC及EC峰值粒径出现为0.65~2.1 μm,但在春季峰值粒径移至2.1~4.7 μm。观测期间,OC与EC质量浓度比值平均为4~6,该比值略高于文献报道的我国一些城市地区的观测结果。Abstract: Carbonaceous aerosols constitute major component of atmospheric aerosols. In Feburay, May, July and September of 2004, size resolved aerosol sampling measurements are conducted respectively at Shangdianzi Regional Atmospheric Background Monitoring Station which is in the suburb of Beijing, to represent the four seasons of the year. OC, EC are analyzed in the lab with Sunset OC/EC Analyzer (NIOSH TOT method, Sunset Lab, USA). The seasonal variations and size distributions of OC and EC composition are characterized, and correlations between OC and EC are discussed as well. The analysis shows that the mean concentration of OC for TSP (Total Suspend Particles) at Shangdianzi Station in the four seasons ranges from 7.5 μg·m-3 to 31.5 μg·m-3, and EC ranges from 1.4 μg·m-3 to 6.6 μg·m-3. As to PM2.1 (particles with aerodynamic diameter less than 2.1 μm), the mean concentrations are from about 4.0 μg·m-3 to 19.1 μg·m-3 for OC, and from about 0.8 μg·m-3 to 4.3 μg·m-3 for EC. The significant seasonal variations of mean OC, EC at Shangdianzi are found with the highest OC and EC concentration appearing in winter and lowest in summer. The size distributions of OC and EC at the Shangdianzi Station shows obvious seasonal differences, with OC and EC peak size at 0.65—2.1 μm during the winter, summer and fall time, and shifts to 2.1—4.7 μm during the spring time. In summer and fall, the OC and EC are mostly concentrated in the fine particles (with particle size less than 2.1 μm). In spring, the size distributions of OC and EC are quite different, where there is a significant enhancement OC, EC mass contents in the coarse particles, which is related to the collision of carbonaceous aerosols with dust particles rich in the spring atmosphere. The mass of organic matter ([OM]=1.4[OE]) in PM2.1 accounts for about 43%—80% of the total mass of OM, and EC in PM2.1 accounts for 54%—70% of total EC. The average ratio of OC and EC for the whole period of sampling is about 4.0—6.0, which is similar with the reported values obtained at many urban sites of China, when considering the difference between the OC, EC laboratory analysis methods. The square correlation coefficients (R2) between OC and EC in winter, spring and fall are 0.84, 0.81, and 0.73 respectively. However, the correlation coefficient is lowest in summer, with R2 about 0.49. This seasonal pattern of correlations indicates the complications for sources and production or removal processes of the carbonaceous aerosols in summer time in that region.
-
Key words:
- aerosol;
- organic carbon (OC);
- elemental carbon (EC);
- size distributions
-
表 1 上甸子站不同季节气溶胶TSP,PM11,PM2.1中OC,EC质量浓度和OC与EC的比值以及OC和OM占气溶胶质量浓度的百分比
Table 1 Mass concentrations and ratios of OC and EC, and percentages of OC and OM in their respective total mass for TSP, PM11, and PM2.1 in different seasons at Shangdianzi Station
气溶胶粒子 采样日期 平均值 (标准差)/(μg·m-3) OC平均值 (标准差)/(μg·m-3) EC平均值 (标准差)/(μg·m-3) TC平均值 (标准差)/(μg·m-3) OC质量百分比/% OM质量百分比/% TSP 2004-02 155.96(105.75) 31.52(20.85) 6.64(5.53) 38.17(26.27) 20.2 28.3 2004-05 110.44(54.38) 9.50(3.35) 1.44(0.82) 10.95(4.13) 8.6 12.0 2004-07 91.42(55.58) 7.56(3.43) 1.90(1.09) 9.47(4.26) 8.3 11.6 2004-09 143.57(68.29) 20.51(11.25) 3.92(1.46) 24.43(12.51) 14.3 20.0 PM11 2004-02 135.15(98.04) 26.87(18.71) 5.93(5.29) 32.80(23.83) 19.9 27.8 2004-05 85.38(48.25) 7.05(2.55) 1.28(0.78) 8.33(3.29) 8.3 11.6 2004-07 85.10(53.68) 6.77(3.04) 1.66(0.87) 8.43(3.71) 8.0 11.1 2004-09 133.95(66.31) 19.36(11.04) 3.54(1.37) 22.90(12.22) 14.5 20.2 PM2.1 2004-02 76.86(65.59) 19.11(14.45) 4.33(3.81) 23.44(18.17) 24.9 34.8 2004-05 33.40(20.92) 4.09(1.60) 0.78(0.43) 4.88(2.00) 12.3 17.2 2004-07 66.01(44.46) 5.07(2.66) 1.26(0.66) 6.33(3.16) 7.7 10.8 2004-09 92.77(51.25) 16.37(10.36) 2.74(1.12) 19.11(11.27) 17.6 24.7 表 2 上甸子站PM2.1中OC, EC相关统计及与我国其他地区测量结果的比较 (其他地区为PM2.5)
Table 2 The correlations between OC and EC for PM2.1 at Shangdianzi Station and the comparisons with the results (for PM2.5) observed in other regions of China
地点 时间 R2 比值 分析方法 文献来源 广州新垦 2002-04 0.57 7.38 NIOSH TOT 刘新民等[41] 2002-11 0.83 5.08 广州 2002-04 0.81 5.46 2002-11 0.95 8.69 北京 1999-07—2000-06 2.72 IMPROVE TOR Yang等[18] 上海 1999-03—2000-03 2.39 北京 2003-01 0.94 1.87 R & P 5400 Yu等[19] 2003-08 0.81 2.39 北京 2004年冬季 0.82 4.36 NIOSH TOT 郇宁等[40] 珠江三角洲 2002年冬季 0.82 2.5 IMPROVE TOR Cao等[17, 30] 2002年夏季 0.63 2.5 太原 2005-12—2006-02 7.0 NIOSH TOT 孟昭阳等[23] 北京上甸子 2004-02 0.94 4.4 NIOSH TOT 本研究 2004-05 0.81 5.2 2004-07 0.49 4.0 2004-09 0.63 6.0 -
[1] Zhang R J, Cao J J, Lee S C, et al. Carbonaceous aerosols in PM10 and pollution gases in winter in Beijing. Journal of Environmental Sciences, 2007, 19: 564-571. doi: 10.1016/S1001-0742(07)60094-1 [2] Turpin B J, Lim H. Species contribution to PM2.5 concentrations: Revisiting common assumptions for estimating organic mass. Aerosol Sci Technol, 2001, 35: 602-610. doi: 10.1080/02786820119445 [3] Chow J C, Watson J G, Chen L W A, et al. Equivalence of elemental carbon by thermal/optical reflectance and transmittance with different temperature protocols. Evironmental Science and Techonology, 2004, 38: 4414-4422. doi: 10.1021/es034936u [4] Malm W C, James F S, Dale H. Spatial and seasonal trends in particle concentration and optical extinction in the united states. J Geophy Res, 1994, 99(D1): 1347-1370. doi: 10.1029/93JD02916 [5] Gundel L A, Guyot-Sionnet N S, Novakov T. A study of NO2 with carbon particles. Aerosol Science & Technology, 1989, 10: 345-351. https://www.researchgate.net/publication/23812445_The_enhanced_oxidation_of_SO2_by_NO2_on_carbon_particulates [6] IPCC. Climate Change 2007: The Physical Science Basis. Cambridge: Cambridge University Press, 2007. [7] Jacobson M Z. Strong radiative heating due to the mixing state of black carbon in atmospheric aerosols. Nature, 2001, 409: 695-697. doi: 10.1038/35055518 [8] Menon S, Hansen J, Nazarenko L, et al. Climate effects of black carbon aerosols in China and India. Science, 2002, 297: 2250-2253. doi: 10.1126/science.1075159 [9] Ramanathan V, Crutzen P J, Kiehl J T, et al. Aerocols, climate, and the hydrological cycle. Science, 2001, 294: 2119-2124. doi: 10.1126/science.1064034 [10] 张瑛, 高庆先.硫酸盐和碳黑气溶胶辐射效应的研究.应用气象学报, 1997, 8(增刊): 87-91. http://www.cnki.com.cn/Article/CJFDTOTAL-YYQX7S1.011.htm [11] Appel B R, Colodny P, Wesolowski J J. Analysis of carbonaceous materials in Southern California atmospheric aerosols. Environmental Science and Technology, 1976, 10(4): 359-363. doi: 10.1021/es60115a005 [12] Gray H A, Gass G R. Characteristics of atmospherico organic and elemental carbon particle concentrations in Los Angeles. Environmental Science and Technology, 1986, 20: 580-589. doi: 10.1021/es00148a006 [13] Chow J C, Watson J G. PM2.5 carbonacate concentrations at regionally representative interagency monotoring of protected visual environment sites. J Geophy Res, 2002, 107(D21): 8344, doi: 10.1029/2001JD000574. [14] Macias E S, Zwicker J O, Ouimette J R, et al. Regional haze case studies in the Southwestern US—I Aerosol chemical composition. Atmos Environ, 1981, 15: 1971-1986. doi: 10.1016/0004-6981(81)90231-6 [15] Vasconcelos L A, Macias E S, White W H. Aerosol composition as a function of haze and humidity levels in the southwestern US. Atmos Environ, 1994, 28: 3679-3691. doi: 10.1016/1352-2310(94)00187-P [16] Bergin M, Cass G R, Xu J, et al. Aerosol radiative, physical, and chemical properties in Beijing during June 1999. J Geophys Res, 2001, 106(D16): 17969-17980. doi: 10.1029/2001JD900073 [17] Cao J J, Lee S C, Ho K F, et al. Spatial and seasonal variations of atmospheric organic carbon and elemental carbon in Pearl River Delta Region, China. Atmos Environ, 2004, 38: 4447-4456. doi: 10.1016/j.atmosenv.2004.05.016 [18] Yang F, He K, Ye B, et al. One-year record of organic and elemental carbon in fine particles in downtown Beijing and Shanghai. Atmos Chem Phys, 2005, 5: 1449-1457. doi: 10.5194/acp-5-1449-2005 [19] Yu J, Chen T, Guinot B, et al. Characteristics of carbonaceous particles in Beijing during winter and summer 2003. Adv Atmos Sci, 2006, 23(3): 468-473. doi: 10.1007/s00376-006-0468-5 [20] 郇宁, 曾立民, 邵敏.气溶胶中有机碳及元素碳分析方法进展.北京大学学报:自然科学版, 2005, 41(6): 957-964. http://www.cnki.com.cn/Article/CJFDTOTAL-BJDZ200506016.htm [21] 张养梅, 颜鹏, 杨东贞, 等.临安大气气溶胶理化特性季节变化.应用气象学报, 2007, 18(5): 635-644. http://qikan.camscma.cn/jams/ch/reader/view_abstract.aspx?file_no=20070598&flag=1 [22] 汤洁, 温玉璞, 周凌晞, 等.中国西部大气清洁地区黑碳气溶胶的观测研究.应用气象学报, 1999, 10(2): 160-170. http://qikan.camscma.cn/jams/ch/reader/view_abstract.aspx?file_no=19990255&flag=1 [23] 孟昭阳, 张怀德, 蒋晓明, 等.太原冬季PM2.5中有机碳和元素碳的变化特征.应用气象学报, 2007, 18(4): 524-531. http://qikan.camscma.cn/jams/ch/reader/view_abstract.aspx?file_no=20070482&flag=1 [24] 唐小玲, 毕新慧, 陈颖军, 等.不同粒径大气颗粒物中有机碳 (OC) 和元素碳 (EC) 的分布.环境科学研究, 2006, 19(1): 104-108. http://cdmd.cnki.com.cn/Article/CDMD-80165-2005128945.htm [25] Kanakidou M, Seinfeld J H, Pandis S N, et al. Organic aerosol and global climate modelling: A review. Atmospheric Chemistry and Physics, 2005, 5(4): 1053-1123. doi: 10.5194/acp-5-1053-2005 [26] 颜鹏, 刘桂清, 周秀骥, 等.上甸子秋冬季雾霾期间气溶胶光学特性.应用气象学报, 2010, 21(3): 257-265. http://qikan.camscma.cn/jams/ch/reader/view_abstract.aspx?file_no=20100301&flag=1 [27] 颜鹏, 张养梅, 杨东贞, 等. 2003年夏季临安地区大气气溶胶离子成分的尺度分布特征.气象学报, 2005, 63(6): 980-987. doi: 10.11676/qxxb2005.093 [28] Birch M E, Cary R A. Elemental carbon-base method for monitoring occupational exposures to particulate diesel exhaust. Aerosol Sci Technol, 1996, 25: 221-241. doi: 10.1080/02786829608965393 [29] Chow J C, Watson J G, Crow D, et al. Comparison of IMPROVE and NIOSH carbon measurements. Aerosol Science and Technology, 2001, 34: 23-34. doi: 10.1080/02786820119073 [30] Cao J J, Lee S C, Ho K F, et al. Characteristics of carbonaceous aerosol in Pearl River Delta Region, China during 2001 winter period. Atmos Environ, 2003, 37: 1451-1460. doi: 10.1016/S1352-2310(02)01002-6 [31] Duce R A, Mohnen V A, Zimmerman P R, et al. Organic material in the global tropopause (troposphere). Rev Geophys Space Phys, 1983, 21: 921-952. doi: 10.1029/RG021i004p00921 [32] Countess R J, Wolff G T, Cadle S H. The Denver winter aerosol: A comprehensive chemical characterization. J Air Pollut Control Assoc, 1980, 30: 1194-1200. doi: 10.1080/00022470.1980.10465167 [33] Ye B M, Ji X L, Yang H Z, et al. Concentration and chemical composition of PM2.5 in Shanghai in one-year period. Atmos Environ, 2003, 37: 499-510. http://www.doc88.com/p-7758292471842.html [34] Sun Y L, Zhuang G S, Ying W, et al. The air-borne particulate pollution in Beijing—Concentration, composition, distribution and sources. Atmos Environ, 2004, 38: 5991-6004. doi: 10.1016/j.atmosenv.2004.07.009 [35] Xu J, Bergin M H, Yu X, et al. Measurement of aerosol chemical, physical, and radiative properties in the Yangtze Delta Region of China. Atmos Environ, 2002, 36: 161-173. doi: 10.1016/S1352-2310(01)00455-1 [36] Chuang P Y, Duvall R M, Bae M S, et al. Observations of elemental carbon and absorption during ACE-Asia and implications for aerosol radiative properties and climate forcing. J Geophys Res, 2003, 108(D23): 8634, doi: 10.1029/2002JD003254. [37] Seinfeld J H, Pandis S N. Atmopsheirc Chemistry and Physics:From Air Pollution to Climate Change. New York: John Wiley & Sons, 1997. [38] 胡敏, 赵云良, 何凌燕, 等.北京冬、夏季颗粒物及其离子成分质量浓度谱分布.环境科学, 2005, 26(4): 1-6. http://www.cnki.com.cn/Article/CJFDTOTAL-HJKZ200504001.htm [39] Novakov T, Menon S, Kirchstetter T W, et al. Aerosol organic to black carbon ratios: Analysis of published data and implications for climate forcing. J Geophys Res, 2005, 110, D21205, doi: 10.1029/2005JD005977. [40] 郇宁, 曾立民, 邵敏, 等.北京市冬季PM215中碳组分的测量与分析.北京大学学报:自然科学版, 2006, 42(2): 265-270. http://www.cnki.com.cn/Article/CJFDTOTAL-BJDZ200602026.htm [41] 刘新民, 邵敏, 曾立民, 等.珠江三角洲地区气溶胶中含碳物质的研究.环境科学, 2002, 23(增刊):54-59. http://www.cnki.com.cn/Article/CJFDTOTAL-HJKZ2002S1011.htm