In situ measurements of trace gases and aerosol optical properties at a rural site in northern China during East Asian Study of Tropospheric Aerosols: An International Regional Experiment 2005
In situ measurements of trace gases and aerosol optical properties at a rural site in northern China during East Asian Study of Tropospheric Aerosols: An International Regional Experiment 2005
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DOI：
10.1029/2006jd007592
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发表时间：
2007-11
影响因子：
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通讯作者：
Can Li;L. Marufu;R. Dickerson;Zhanqing Li;T. Wen;Yuesi Wang;Pucai C. Wang;Hongbin Chen;J. Stehr-J.
中科院分区：
文献类型：
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作者：
Can Li;L. Marufu;R. Dickerson;Zhanqing Li;T. Wen;Yuesi Wang;Pucai C. Wang;Hongbin Chen;J. Stehr-J.
[1] 2005年3月，在香河（39.798°N, 116.958°E, 35 m）进行了微量气体和气溶胶光学特性的现场测量，香河位于北京市区东南约70公里的农村地区，通常在顺风方向。该地区CO（1.09±1.02 ppmv，平均值±标准差）、SO2（17.8±15.7 ppbv）、NOy（26.0±24.0 ppbv）、气溶胶散射系数（bsp,（468±472）× 10−6 m−1）和气溶胶吸收系数（bap,（65±75）× 10−6 m−1）均远高于美国部分农村地区的观测值。在本研究中，O3（29.1±16.5 ppbv）相对较低，表明光化学过程不活跃。在试验期间，由于冷锋经过该地区，大大减少了地面污染，每隔4-5天就会检测到污染物水平的强烈天气波动。整个观测期内降水很少，表明污染物的抬升和输送是由无雨冷锋和干对流引起的。观测到的单次散射反照率（SSA）（上午0.81，下午0.85）表明近地表气溶胶被强烈吸收。观测到的CO/SO2比值（35.8）高于库存值，但更接近Streets等人（2006）的更新CO库存，而不是Streets等人（2003）或Wang等人（2005）。观察到的CO/NOy比率与库存更吻合。进一步的分析表明，这种比较可能使人们对排放清单的质量有所了解，但任何误差的量化都需要在更长的时期和更大的地区进行更广泛的测量，以及对排放源，特别是流动源和小型锅炉进行直接描述。利用实验中的黑碳(BC)/CO比值，估计中国的黑碳排放量约为1300 Gg (109 g)/年，但可能高达2600 Gg/年。
[1] In situ measurements of trace gases and aerosol optical properties were made in March 2005 at Xianghe (39.798°N, 116.958°E, 35 m), a rural site about 70 km southeast, and generally downwind of the Beijing metropolitan area. High pollutant levels were observed during the experiment, with CO (1.09 ± 1.02 ppmv, average ± standard deviation), SO2 (17.8 ± 15.7 ppbv), NOy (26.0 ± 24.0 ppbv), aerosol scattering coefficients (bsp, (468 ± 472) × 10−6 m−1), and aerosol absorption coefficients (bap, (65 ± 75) × 10−6 m−1) all much higher than observed at some rural sites in the United States. O3 (29.1 ± 16.5 ppbv) was relatively low during this study, suggesting inactive photochemical processes. Strong synoptic fluctuations in pollutant levels were detected every 4–5 days during the experiment, as cold fronts passing over the region drastically reduced the ground-level pollution. Very little precipitation was measured during the whole observational period, implying pollutant uplift and transport by rain-free cold fronts and dry convection. The single scattering albedo (SSA) observed (0.81 in the morning and 0.85 in the afternoon) indicates strongly absorbing aerosols near surface. The observed CO/SO2 ratio (35.8) is higher than inventory values, but closer to the updated CO inventory of Streets et al. (2006) than to Streets et al. (2003) or Wang et al. (2005). The observed CO/NOy ratio agrees better with inventories. Further analysis suggests that such comparisons may shed some light on the quality of emission inventories, but quantification of any error requires more extensive measurements over longer period and larger areas, as well as direct characterization of emission sources, especially mobile sources and small boilers. Using black carbon (BC)/CO ratio from the experiment, BC emissions from China are estimated at about 1300 Gg (109 g)/yr, but could be as high as 2600 Gg/yr.