Accuracy of black carbon measurements by a filter-based absorption photometer with a heated inlet

Ohata, Sho; Kondo, Yutaka; Moteki, Nobuhiro; Mori, Tatsuhiro; Yoshida, Akitoshi; Sinha, P. R.; Koike, M.

doi:10.1080/02786826.2019.1627283

Cited by 33 publications

(58 citation statements)

References 45 publications

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“…Figure 2 depicts the correlation between EBC COSMOS and rBC SP2 with a time resolution of 1 min and for the 15-min average. EBC COSMOS strongly correlated with rBC SP2 , being generally consistent with previous studies conducted in both urban and remote areas (Kondo et al 2011;Miyakawa et al 2017;Ohata et al 2019). Therefore, we assumed that the EBC COSMOS measurements were approximately equivalent to rBC SP2 .…”

Section: Continuous Soot Monitoring System (Cosmos)supporting

confidence: 89%

“…One exception is marine boundary layers (MBLs) where "thermally inert" sea-salt particles dominate. This is indicated by a previous study using the COSMOS in which includes the heated inlet (Ohata et al 2019). Note that the use of the heated inlet can induce charring of refractory organic materials such as humic-like substances (HULIS), slightly affecting the light-absorption measurements as indicated by Kondo et al (2011).…”

Section: Remaining Issuesmentioning

confidence: 78%

“…The BC mass concentrations measured by the COSMOS are referred to as EBC COSMOS . The uncertainty is 10% (Ohata et al 2019). The COSMOS was calibrated by the manufacturer (Kanomax) before installation.…”

Section: Continuous Soot Monitoring System (Cosmos)mentioning

confidence: 99%

“…Further characterizations of the AE51 are needed for understanding its performance in remote atmosphere with lower BC concentrations than in our study. The use of the heated inlet will minimize the uncertainties regarding nonBC materials, for example major inorganic and organic aerosols in the submicron size range, in a wide variety of atmospheric environment (e.g., remote island, Miyakawa et al 2017;Ohata et al 2019). One exception is marine boundary layers (MBLs) where "thermally inert" sea-salt particles dominate.…”

Section: Remaining Issuesmentioning

confidence: 99%

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Evaluation of black carbon mass concentrations using a miniaturized aethalometer: Intercomparison with a continuous soot monitoring system (COSMOS) and a single-particle soot photometer (SP2)

Miyakawa

Mordovskoi

Kanaya

2020

Aerosol Science and Technology

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Ground-based observations of black carbon (BC) aerosols were conducted in spring 2017 in Yokosuka City, south of Tokyo, Japan. Equivalent BC (EBC) mass concentrations were measured using a miniaturized, palm-sized filter-photometer (MicroAeth AE51, EBC AE51 ) and evaluated against those obtained using a continuous soot monitoring system (COSMOS, EBC COSMOS ) and a single-particle soot photometer (SP2, refractory BC, rBC SP2 ). We propose methods to account for the following key factors affecting AE51 measurements: (1) the nonlinearity of light attenuation (ATN) measurements associated with high-particle loading on the filter (i.e., the loading effect); and (2) the positive artifacts in ATN measurements created by non-refractory materials (nonBC) on the filter. To examine these effects, we employed a custom automated system that switches the two sampling lines for the AE51, one of which was heated to 300 C to minimize the sampling of nonBC. Alternate operation of the heated and unheated modes (for 15 min) enabled the separation of the described effects. Consistent with previous studies, in the heated mode, sensitivity decreased linearly with increases in ATN (À0.44% per ATN) in comparison with the other aethalometers. When the loading effect was corrected for, the EBC AE51 in the unheated mode still showed some bias relative to EBC COSMOS and rBC SP2 . This bias correlated with-and was successfully corrected for using-the mass ratio of nonBC to BC derived from the SP2. This approach can also be applied to fine-mode aerosol (PM 2.5 ) concentrations measured at environmental monitoring networks, thus eliminating the need for additional SP2 data in the data correction. ARTICLE HISTORY

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Section: Continuous Soot Monitoring System (Cosmos)supporting

confidence: 89%

Section: Remaining Issuesmentioning

confidence: 78%

Section: Continuous Soot Monitoring System (Cosmos)mentioning

confidence: 99%

Section: Remaining Issuesmentioning

confidence: 99%

See 2 more Smart Citations

Evaluation of black carbon mass concentrations using a miniaturized aethalometer: Intercomparison with a continuous soot monitoring system (COSMOS) and a single-particle soot photometer (SP2)

Miyakawa

Mordovskoi

Kanaya

2020

Aerosol Science and Technology

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“…cyclone (PM 2.5 before 17 September 2011). Ohata et al (2019) and references therein showed that the average accuracy of the COSMOS was estimated as ~10% under various field environments in the Arctic and in the East Asia. In this paper, the data records from the two instruments were 'unified' to minimize the gaps related to failure of individual instruments.…”

Section: Methodsmentioning

confidence: 99%

Rapid reduction of black carbon emissions from China: evidence from 2009–2019 observations on Fukue Island, Japan

Kanaya¹,

Yamaji²,

Miyakawa³

et al. 2019

Preprint

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Abstract. A long-term, robust observational record of atmospheric black carbon (BC) concentrations at Fukue Island for 2009–2019 was produced by unifying data from a continuous soot-monitoring system and a multi-angle absorption photometer. This record was then used to analyze emission trends from China. We identified a rapid reduction in BC concentrations of (−5.8 ± 1.5) % y−1 or −48 % from 2010 to 2018. We concluded that an emission change of (−5.3 ± 0.7) % y−1, related to changes in China of as much as −4.6 % y−1, was the main underlying driver. This evaluation was made after correcting for the interannual meteorological variability, by using regional atmospheric chemistry model simulations (WRF/CMAQ) with constant emissions. This resolves current fundamental disagreements about the sign of the BC emission trend from China over the past decade, assessed from bottom-up emission inventories; our analysis supported inventories reflecting the governmental clean air actions after 2010 (e.g., MEIC1.3, ECLIPSE v5a and v6b, and REAS updated) and recommended revision to those not (e.g., CEDS). Our estimated emission trends were fairly uniform over seasons but diverse among air-mass origins. Stronger BC reductions occurred in regions of South-Central East China, accompanied by CO emission reduction, while weaker BC reductions occurred in North-Central East China and Northeast China. Prior to 2017, the BC and CO emission trends were both unexpectedly positive in Northeast China during winter months, possibly influencing climate at higher latitudes. The pace of emission reduction over China surpasses those of SSP1 scenarios (SSP: shared socioeconomic pathways) for 2015–2030, suggesting highly successful emission control policies. At Fukue Island, the BC fraction of PM2.5 also steadily decreased over the last decade, suggesting that BC emission reduction started without significant delay with respect to other pollutants, such as NOx and SO2, which are among key precursors of scattering PM2.5.

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Studies on Arctic aerosols and clouds during the ArCS project

et al. 2021

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Accuracy of black carbon measurements by a filter-based absorption photometer with a heated inlet

Cited by 33 publications

References 45 publications

Evaluation of black carbon mass concentrations using a miniaturized aethalometer: Intercomparison with a continuous soot monitoring system (COSMOS) and a single-particle soot photometer (SP2)

Evaluation of black carbon mass concentrations using a miniaturized aethalometer: Intercomparison with a continuous soot monitoring system (COSMOS) and a single-particle soot photometer (SP2)

Rapid reduction of black carbon emissions from China: evidence from 2009–2019 observations on Fukue Island, Japan

Studies on Arctic aerosols and clouds during the ArCS project

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