Measurements of aerosol optical properties in central Tokyo during summertime using cavity ring-down spectroscopy: Comparison with conventional techniques
Measurements of aerosol optical properties in central Tokyo during summertime using cavity ring-down spectroscopy: Comparison with conventional techniques
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DOI：
10.1016/j.atmosenv.2010.05.008
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发表时间：
2010-08
影响因子：
5
通讯作者：
T. Nakayama;R. Hagino;Y. Matsumi;Y. Sakamoto;M. Kawasaki;A. Yamazaki;A. Uchiyama;R. Kudo;N. Moteki;Y. Kondo;K. Tonokura
中科院分区：
文献类型：
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作者：
T. Nakayama;R. Hagino;Y. Matsumi;Y. Sakamoto;M. Kawasaki;A. Yamazaki;A. Uchiyama;R. Kudo;N. Moteki;Y. Kondo;K. Tonokura
利用高灵敏度光腔衰荡光谱仪（CRDS）在532 nm处测量气溶胶消光系数。使用直径在150和500 nm之间的几乎单分散的聚苯乙烯颗粒的测量来评估光谱仪的性能。通过比较观察到的结果与使用米氏理论确定的结果，CRDS仪器的准确度被确定为> 97%，而仪器的精确度的上限估计为0.6-3.5%（通常为2%），这取决于粒子数浓度，其范围为30- 2300个粒子cm-3。同时测量消光（bext），散射（bsca）和吸收（babs）系数的环境气溶胶在东京市中心从2007年8月14日至9月2日使用CRDS仪器，两个浊度计和粒子/烟尘吸收光度计（PSAP），分别。将使用CRDS仪器测量的bext值与分别用浊度计和PSAP测量的bsca和babs值的总和进行比较。除了在高臭氧混合比（> 130 ppbv）的日子，bext和bsca+ babs值之间的一致性很好。在高O3天，bsca+ babs的值比bext的值大0.7%，这可能是因为由PSAP测量的babs的值被高估，由于共存的非吸收性气溶胶，如二次有机气溶胶的干扰。
A highly sensitive cavity ring-down spectrometer (CRDS) was used to monitor the aerosol extinction coefficient at 532nm. The performance of the spectrometer was evaluated using measurements of nearly monodisperse polystyrene particles with diameters between 150 and 500nm. By comparing the observed results with those determined using Mie theory, the accuracy of the CRDS instrument was determined to be >97%, while the upper limit for the precision of the instrument was estimated to be 0.6–3.5% (typically 2%), depending on the particle number concentration, which was in the range of 30–2300particlescm−3. Simultaneous measurements of the extinction (bext), scattering (bsca) and absorption (babs) coefficients of ambient aerosols were performed in central Tokyo from 14 August to 2 September 2007 using the CRDS instrument, two nephelometers and a particle/soot absorption photometer (PSAP), respectively. The value of bextmeasured using the CRDS instrument was compared with the sum of the bscaand babsvalues measured with a nephelometer and a PSAP, respectively. Good agreement between the bextand bsca+babsvalues was obtained except for data on days when high ozone mixing ratios (>130ppbv) were observed. During the high-O3days, the values for bsca+babswere ∼7% larger than the value for bext, possibly because the value for babsmeasured by the PSAP was overestimated due to interference from coexisting non-absorbing aerosols such as secondary organic aerosols.