Collocated comparisons of continuous and filter-based PM2.5 measurements at Fort McMurray, Alberta, Canada.
Collocated comparisons of continuous and filter-based PM2.5 measurements at Fort McMurray, Alberta, Canada.
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DOI：
10.1080/10962247.2015.1136362
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发表时间：
2016-03
期刊：
影响因子：
--
通讯作者：
Percy KE
中科院分区：
文献类型：
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作者：
Hsu YM;Wang X;Chow JC;Watson JG;Percy KE
2011年6月至2013年5月，在加拿大阿尔伯塔麦克默里堡（位于阿萨巴斯卡油砂地区的一个城市）居民区的一个空气监测站，对三个PM2.5监测器进行了并列比较。极端寒冷的冬季（低至约-40 °C）加上PM2.5浓度低，对连续测量提出了挑战。锥形元件振荡微量天平（TEOM），在40°C（即，TEOM 40）和同步混合环境实时颗粒物（SHARP，联邦等效方法[FEM]）与Partisol PM2.5美国联邦参考方法（FRM）采样器进行比较。虽然每小时TEOM 40 PM2.5始终比SHARP低约20-50%，但FRM和SHARP的24小时平均值之间没有统计学显著差异。使用从FRM和TEOM 40导出的正交回归（OR）方程来调整TEOM 40（即，TEOMadj），并改善其与FRM的协议，特别是在寒冷的季节。基于SHARP和TEOM 40之间的OR方程，从1999年至2011年的12年每小时TEOMadj测量值来自2年（2011-2013年）的同位测量值。结合TEOMadj和SHARP测量的趋势分析显示，从1999年到2014年，PM2.5浓度呈统计学显著下降，季节性斜率为-0.15 μg m-3 yr-1。3台PM2.5监测仪的配置比较显示了FRM与TEOM、SHARP与TEOM之间的差异。正交回归方程可用于校正历史TEOM数据，以检查网络内的长期趋势。
Collocated comparisons for three PM2.5 monitors were conducted from June 2011 to May 2013 at an air monitoring station in the residential area of Fort McMurray, Alberta, Canada, a city located in the Athabasca Oil Sands Region. Extremely cold winters (down to approximately −40°C) coupled with low PM2.5 concentrations present a challenge for continuous measurements. Both the tapered element oscillating microbalance (TEOM), operated at 40°C (i.e., TEOM40), and Synchronized Hybrid Ambient Real-time Particulate (SHARP, a Federal Equivalent Method [FEM]), were compared with a Partisol PM2.5 U.S. Federal Reference Method (FRM) sampler. While hourly TEOM40 PM2.5 were consistently ~20–50% lower than that of SHARP, no statistically significant differences were found between the 24-hr averages for FRM and SHARP. Orthogonal regression (OR) equations derived from FRM and TEOM40 were used to adjust the TEOM40 (i.e., TEOMadj) and improve its agreement with FRM, particularly for the cold season. The 12-year-long hourly TEOMadj measurements from 1999 to 2011 based on the OR equations between SHARP and TEOM40 were derived from the 2-year (2011–2013) collocated measurements. The trend analysis combining both TEOMadj and SHARP measurements showed a statistically significant decrease in PM2.5 concentrations with a seasonal slope of −0.15 μg m−3 yr−1 from 1999 to 2014.Implications: Consistency in PM2.5 measurements are needed for trend analysis. Collocated comparison among the three PM2.5 monitors demonstrated the difference between FRM and TEOM, as well as between SHARP and TEOM. The orthogonal regressions equations can be applied to correct historical TEOM data to examine long-term trends within the network.