气候变化领域集成服务门户(CCPortal): Implications of Organic Mass to Carbon Ratios Increasing Over Time in the Rural United States

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DOI	10.1029/2019JD031480
	Implications of Organic Mass to Carbon Ratios Increasing Over Time in the Rural United States
	Malm W.C.; Schichtel B.A.; Hand J.L.; Prenni A.J.
发表日期	2020
ISSN	2169897X
卷号	125 期号:5
英文摘要	The thermal evolution procedure used by most monitoring programs in the United States to determine carbonaceous aerosol concentrations is referred to as the thermal-optical reflectance method, where an aerosol sample that has been collected on a quartz filter is heated and evolved carbon is characterized as either organic (OC) or light absorbing carbon (LAC). Evolved carbon assigned to OC is multiplied by a factor, Roc, to achieve an estimate of organic mass. Over the last 10–15 years, Roc, estimated through multiple linear regression analysis of data collected in the Interagency Monitoring of Protected Visual Environments (IMPROVE) program, has increased at about a rate of about 0.02 per year, reaching values above 2.0 in many regions of the United States. Analysis of evolved carbon concentration temporal trends suggests that thermal-optical reflectance analysis, on the average, inaccurately bifurcates particulate carbon into the OC and LAC fractions with some LAC being inadvertently and wrongly assigned to the OC fraction. It is shown that misapportioned LAC assigned to OC is decreasing faster than true OC, resulting in a compensating increase in the Roc assigned to reported OC over time. A first-order model is proposed to correct for the misapportioned carbon. ©2020. American Geophysical Union. All Rights Reserved.
英文关键词	Carbon Measurement Uncertainty; Elemental Carbon; Organic Carbon; Organic Carbon to Carbon Ratio; Thermal Optical Reflectance
语种	英语
来源期刊	Journal of Geophysical Research: Atmospheres
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/186142
作者单位	Cooperative Institute for Research in the Atmosphere, Colorado State University, Fort Collins, CO, United States; National Park Service, Air Resources Division, Lakewood, CO, United States
推荐引用方式 GB/T 7714	Malm W.C.,Schichtel B.A.,Hand J.L.,et al. Implications of Organic Mass to Carbon Ratios Increasing Over Time in the Rural United States[J],2020,125(5).
APA	Malm W.C.,Schichtel B.A.,Hand J.L.,&Prenni A.J..(2020).Implications of Organic Mass to Carbon Ratios Increasing Over Time in the Rural United States.Journal of Geophysical Research: Atmospheres,125(5).
MLA	Malm W.C.,et al."Implications of Organic Mass to Carbon Ratios Increasing Over Time in the Rural United States".Journal of Geophysical Research: Atmospheres 125.5(2020).