Intercomparison of two different thermal-optical elemental carbons and optical black carbon during ABC-EAREX2005
Intercomparison of two different thermal-optical elemental carbons and optical black carbon during ABC-EAREX2005
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DOI：
10.1016/j.atmosenv.2006.11.040
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发表时间：
2007-04
影响因子：
5
通讯作者：
M. Bae;C. Hong;Young J. Kim;Jin S. Han;Kwang-Ju Moon;Y. Kondo;Y. Komazaki;Y. Miyazaki
中科院分区：
文献类型：
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作者：
M. Bae;C. Hong;Young J. Kim;Jin S. Han;Kwang-Ju Moon;Y. Kondo;Y. Komazaki;Y. Miyazaki
采用三种实时半连续测量系统，对细粒元素(黑)碳进行了正式比对。在2005年大气棕云-东亚区域实验(ABC-EAREX2005)活动期间，在韩国高山进行了两小时间隔的有机碳(OC)和元素碳(EC)的时间分辨测量。它们由日落实验室相同的半连续野外碳素仪器(热光透过率)在PM2.5颗粒物中操作。然而，他们的加热方案(OC为四步和两步，EC为五步和两步)是不同的。为了进行比对研究，我们用风速计比较了共定位1min的黑碳(BC)浓度。因此，两种不同温度方案之间OC的低R2表明，最高温度(870和840°C)和一些温度步骤(四个步骤和两个步骤)与其保持时间的微小差异可能会显著增加OC的偏差。而EC占总碳(TC)的比例较小，在2%O2和98%He的混合气氛下，6个温阶和2个温阶最高可达900℃和880°C，斜率为1.05±0.15(R2=0.98)，表现出良好的一致性。EC和BC的斜率不同，变化范围为1.23-1.61，反映了BC颗粒物衰减系数的变异性。
A formal intercomparison of fine particle elemental (black) carbon is conducted involving three real-time semi-continuous measurement systems. Two-hourly interval time-resolved measurements of organic carbon (OC) and elemental carbon (EC) were performed at the Gosan site, Korea during Atmospheric Brown Clouds–East Asian Regional Experiment 2005 (ABC-EAREX2005) campaign. They were operated by the same semi-continuous field carbon instruments of Sunset Laboratory (thermal optical transmittance) in PM2.5particulate. However, their thermal protocols (four and two steps for OC and five and two steps for EC) were different. The co-located 1min black carbon (BC) concentrations were compared by an Aethalometer for an intercomparison study. As a result, the poor R2of OC between two different temperature protocols suggested that OC can be significantly more biased by the slight differences of maximum temperature (870 and 840°C) and a number of temperature steps (four steps and two steps) with their hold times. However, EC that is a smaller fraction of total carbon (TC) shows the good agreement between two different protocols, which are under a mixture of 2% O2and 98% He in six temperature steps and two temperature steps as max as 900 and 880°C with the slope of 1.05±0.15 (R2of 0.98). The different slopes between EC and BC, which show the range of 1.23–1.61, demonstrate the variability of the attenuation coefficient of the BC particulate.