Time-resolved measurements of water-soluble organic carbon in Tokyo
Time-resolved measurements of water-soluble organic carbon in Tokyo
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DOI：
10.1029/2006jd007125
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发表时间：
2006-12-12
影响因子：
4.4
通讯作者：
Weber, R. J.
中科院分区：
文献类型：
--
作者：
Miyazaki, Y.;Kondo, Y.;Weber, R. J.
[1]半连续测量亚微米水溶性有机碳（WSOC）气溶胶的同时，有机碳（OC）和元素碳（EC）在东京市区的冬，夏，秋2004年。WSOC和OC/EC的测量，每6分钟和1小时，分别使用颗粒进液采样器（PILS）与总有机碳（TOC）分析仪和EC-OC分析仪使用热光学技术。WSOC的PILS和12小时综合过滤器测量值在12%以内。WSOC质量浓度和WSOC/OC比值均表现出明显的日变化，夏季在1200-1400 LT出现峰值，冬季在下午出现峰值。平均而言，WSOC/OC比为0.20和0.35 μ g C/μ g C的冬季和夏季/晚秋，分别。冬季和夏季的WSOC/OC比值的频率分布的差异表明，在夏季和秋季采样的空气质量比冬季更多的光化学处理。次生有机碳（SOC）的浓度估计使用EC示踪法。实测的WSOC与推导出的SOC高度相关（r（2）= 0.61-0.79），每个季节WSOC/SOC的斜率为0.67 - 0.75 μ g C/μ g C。这些结果表明，在本研究中，WSOC和SOC的化学特征相似。水不溶性有机碳（WIOC）（= OC-WSOC）与EC和CO具有良好的相关性（r（2）= 0.59-0.73）。在整个研究期间，日平均WIOC/EC比率几乎恒定（1.1 +/- 0.1 μ g C/μ g C），表明机动车排放是WIOC的重要来源。POC的主要部分（约90%或更多）是水不溶性的，与以前的研究POC一致。
[1] Semicontinuous measurements of submicron water-soluble organic carbon (WSOC) aerosol were made simultaneously with organic carbon (OC) and elemental carbon (EC) in the Tokyo urban area in winter, summer, and fall 2004. The measurements of WSOC and OC/EC were made every 6 min and 1 hour, respectively, using a particle-into-liquid sampler (PILS) with a total organic carbon (TOC) analyzer and with an EC-OC analyzer using a thermal-optical technique. The PILS and 12-hour integrated filter measurements of WSOC agreed to within 12%. The WSOC mass concentrations and WSOC/OC ratio showed diurnal variations with peaks at 1200-1400 LT in summer and later in the afternoon in winter. On average, the WSOC/OC ratio was 0.20 and 0.35 mu g C/mu g C for winter and summer/late fall, respectively. The difference in the winter and summer frequency distributions of the WSOC/OC ratio suggests that the sampled air masses in summer and fall were more photochemically processed than those in winter. Secondary organic carbon (SOC) concentrations were estimated using the EC-tracer method. The measured WSOC was highly correlated with the derived SOC (r(2) = 0.61-0.79), with WSOC/SOC slopes of 0.67 to 0.75 mu g C/mu g C for each season. These results suggest that the WSOC and SOC were similar in their chemical characteristics in this study. Water-insoluble organic carbon (WIOC) ( = OC-WSOC) correlated well with EC and CO (r(2) = 0.59-0.73). The diurnally averaged WIOC/EC ratios were nearly constant (1.1 +/- 0.1 mu g C/mu g C) throughout the study periods, suggesting that motor vehicle emissions were an important source of WIOC. A dominant portion ( about 90% or more) of the POC was water-insoluble, consistent with previous studies of POC.