Comparison of Filter-based Absorption Measurements of Biomass Burning Aerosol and Background Aerosol at the Mt. Bachelor Observatory
Comparison of Filter-based Absorption Measurements of Biomass Burning Aerosol and Background Aerosol at the Mt. Bachelor Observatory
复制标题
DOI：
10.4209/aaqr.2019.06.0298
复制
发表时间：
2020
影响因子：
4
通讯作者：
J. Laing;D. Jaffe;A. Sedlacek
中科院分区：
文献类型：
--
作者：
J. Laing;D. Jaffe;A. Sedlacek
摘要在这项研究中，我们评估了最近升级的aethalometer（AE 33）和新发布的三色吸收光度计（TAP）在他们部署在山学士天文台（MBO; 2763米a.s.l.）野火气溶胶羽流的反应。2016年夏天，美国中部俄勒冈州。虽然这两个文书使用类似的方法（即，通过载有气溶胶的过滤器的光消光），每种都具有一组独特的校正方案，以解决源自过滤器负载、来自捕获的气溶胶颗粒的散射以及过滤器纤维的多重散射效应的伪像。我们还利用单粒子烟尘光度计（SP2）来确定这些气团中的耐火炭黑（rBC）。除了比较AE 33的过滤器加载校正方法，以前出版的aethalometer校正方案，我们还比较了AE 33的校正方案用于TAP和评估的程度不同的校正因子影响推导出的吸收？ngstr？？m指数（AAE）和质量吸收截面（MAC）。我们发现，而不同的校正因子的AE 33或TAP不施加影响的派生MAC，AAE表现出最敏感的校正方案。我们的研究发现，使用AE 33制造商？的建议设置导致气溶胶光吸收系数比TAP报告的气溶胶光吸收系数大3.4至4倍。通过将AE 33标准化以匹配TAP，我们计算出AE 33的校正因子（Cf）为4.35。未校正的AE 33也给出了等效的黑碳（eBC）值，约为SP2仪器测量的rBC的2倍。我们还发现，生物质燃烧气溶胶导致显着的MAC增强，特别是在较低的波长，这是由于棕色碳（BrC）。
ABSTRACT In this study we evaluate the recently upgraded aethalometer (AE33) and the newly released tricolor absorption photometer (TAP) with respect to their response to wildfire aerosol plumes during their deployment at the Mount Bachelor Observatory (MBO; 2763 m a.s.l.) in central Oregon, USA, during the summer of 2016. While both instruments use similar methodology (i.e., light extinction through an aerosol-laden filter), each has a unique set of correction schemes to address artifacts originating from filter loading, scattering from captured aerosol particles, and multiple scattering effects of the filter fibers. We also utilize a Single Particle Soot Photometer (SP2) to determine refractory black carbon (rBC) in these air masses. In addition to comparing the AE33 filter-loading correction methodology to previously published aethalometer correction schemes, we also compare the AE33 to the correction schemes used for the TAP and evaluate the degree to which the different correction factors influence the derived absorption ??ngstr??m exponents (AAE) and mass absorption cross sections (MACs). We find that while the different correction factors for either the AE33 or TAP do exert an influence on the derived MACs, AAEs exhibit the most sensitivity to the correction schemes. Our study finds that using the AE33 manufacturer???s recommended settings results in aerosol light absorption coefficients that are 3.4 to 4 times greater than the aerosol light absorption coefficients reported by the TAP. We calculated a correction factor (Cf) of 4.35 for the AE33 by normalizing the AE33 to match the TAP. The uncorrected AE33 also gives equivalent black carbon (eBC) values that are approximately 2 times the rBC measured by the SP2 instrument. We also find that biomass burning aerosols result in significant MAC enhancements, particularly at lower wavelengths, which is attributable to brown carbon (BrC).