Multi-angle absorption photometry—a new method for the measurement of aerosol light absorption and atmospheric black carbon

Petzold, A.; Schönlinner, M.

doi:10.1016/j.jaerosci.2003.09.005

Cited by 588 publications

(522 citation statements)

References 30 publications

(52 reference statements)

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“…Comparisons of simultaneous measurements made using PAS and filter-based techniques (PSAP, aethalometer, integrating plate) show considerable differences (up to a factor of two) under some circumstances, especially when the relative humidity is variable (Moosmüller et al, 1998;Arnott et al, 1999;Arnott et al, 2003;Sheridan et al, 2005). The most reliable filter-based instrument for absorption measurements at this time is the multi-angle absorption photometer (MAAP), which simultaneously measures transmittance and reflectance of the filter at multiple angles and uses a twostream radiative transfer model to determine the filter and aerosol scattering corrections for the absorption measurement (Petzold and Schönlinner, 2004). …”

Section: Problems Related To the Measurement Of Aerosol Light Absorptionmentioning

confidence: 99%

Black carbon or brown carbon? The nature of light-absorbing carbonaceous aerosols

Andreae

Gelencsér²

2006

Atmos. Chem. Phys.

1,761

1,033

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Abstract. Although the definition and measurement techniques for atmospheric "black carbon" ("BC") or "elemental carbon'' ("EC") have long been subjects of scientific controversy, the recent discovery of light-absorbing carbon that is not black ("brown carbon, Cbrown") makes it imperative to reassess and redefine the components that make up light-absorbing carbonaceous matter (LAC) in the atmosphere. Evidence for the atmospheric presence of Cbrown comes from (1) spectral aerosol light absorption measurements near specific combustion sources, (2) observations of spectral properties of water extracts of continental aerosol, (3) laboratory studies indicating the formation of light-absorbing organic matter in the atmosphere, and (4) indirectly from the chemical analogy of aerosol species to colored natural humic substances. We show that brown carbon may severely bias measurements of "BC" and "EC" over vast parts of the troposphere, especially those strongly polluted by biomass burning, where the mass concentration of Cbrown is high relative to that of soot carbon. Chemical measurements to determine "EC" are biased by the refractory nature of Cbrown as well as by complex matrix interferences. Optical measurements of "BC" suffer from a number of problems: (1) many of the presently used instruments introduce a substantial bias into the determination of aerosol light absorption, (2) there is no unique conversion factor between light absorption and "EC" or "BC" concentration in ambient aerosols, and (3) the difference in spectral properties between the different types of LAC, as well as the chemical complexity of Cbrown, lead to several conceptual as well as practical complications. We also suggest that due to the sharply increasing absorption of Cbrown towards the UV, single-wavelength light absorption measurements may not be adequate for the assessment of absorption of solar radiation in the troposphere. We discuss the possible consequences of these effects for our understanding of tropospheric processes, including their influence on UV-irradiance, atmospheric photochemistry and radiative transfer in clouds.

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Section: Problems Related To the Measurement Of Aerosol Light Absorptionmentioning

confidence: 99%

Black carbon or brown carbon? The nature of light-absorbing carbonaceous aerosols

Andreae

Gelencsér²

2006

Atmos. Chem. Phys.

1,761

1,033

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“…At this station, BC is measured with Multi-Angle Absorption Photometry (MAAP, Petzold and Schonlinner, 2004;Petzold et al, 2005) at 1 min resolution.…”

Section: Complementary Stationary Measurementsmentioning

confidence: 99%

Mobile monitoring for mapping spatial variation in urban air quality: Development and validation of a methodology based on an extensive dataset

Bossche

Peters

Verwaeren

et al. 2015

Atmospheric Environment

191

132

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Mobile monitoring is increasingly used as an additional tool to acquire air quality data at a high spatial resolution. However, given the high temporal variability of urban air quality, a limited number of mobile measurements may only represent a snapshot and not be representative. In this study, the impact of this temporal variability on the representativeness is investigated and a methodology to map urban air quality using mobile monitoring is developed and evaluated.A large set of black carbon (BC) measurements was collected in Antwerp, Belgium, using a bicycle equipped with a portable BC monitor (micro-aethalometer). The campaign consisted of 256 and 96 runs along two fixed routes (2 and 5 km long). Large gradients over short distances and differences up to a factor of 10 in mean BC concentrations aggregated at a resolution of 20 m are observed. Mapping at such a high resolution is possible, but a lot of repeated measurements are required. After computing a trimmed mean and applying background normalisation, depending on the location 24 to 94 repeated measurement runs (median of 41) are required to map the BC concentrations at a 50 m resolution with an uncertainty of 25 %. When relaxing the uncertainty to 50 %, these numbers reduce to 5 to 11 (median of 8) runs. We conclude that mobile monitoring is a suitable approach for mapping the urban air quality at a high spatial resolution, and can provide insight into the spatial variability that would not be possible with stationary monitors. A careful set-up is needed with a sufficient number of repetitions in relation to the desired reliability and spatial resolution. Specific data processing methods such as background normalisation and event detection have to be applied.

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“…A detailed description of the MAAP is provided in the literature (Petzold et al 2002;Petzold and Schönlinner 2004). In this instrument, particles are deposited on a quartz fiber filter.…”

Section: Multi-angle Absorption Photometer (Maap)mentioning

confidence: 99%

An Inter-Comparison of Instruments Measuring Black Carbon Content of Soot Particles

Slowik

Cross

Han

et al. 2007

Aerosol Science and Technology

Self Cite

287

245

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Inter-comparison studies of well-characterized fractal soot particles were conducted using the following four instruments: Aerosol Mass Spectrometer-Scanning Mobility Particle Sizer (AMS-SMPS), Single Particle Soot Photometer (SP2), Multi-Angle Absorption Photometer (MAAP), and Photoacoustic Spectrometer (PAS). These instruments provided measurements of the refractory mass (AMS-SMPS), incandescent mass (SP2) and optically absorbing mass (MAAP and PAS). The particles studied were in the mobility diameter range from 150 nm to 460 nm and were Address correspondence to P. Davidovits, Chemistry Department, Boston College, Merkert Chemistry Center 223, 140 Commonwealth Avenue, Chestnut Hill, MA 02467, USA. E-mail: paul.davidovits@ bc.edu generated by controlled flames with fuel equivalence ratios ranging between 2.3 and 3.5. The effect of organic coatings (oleic acid and anthracene) on the instrument measurements was determined. For uncoated soot particles, the mass measurements by the AMS-SMPS, SP2, and PAS instruments were in agreement to within 15%, while the MAAP measurement of optically-absorbing mass was higher by ∼50%. Thin organic coatings (∼10 nm) did not affect the instrument readings. A thicker (∼50 nm) oleic acid coating likewise did not affect the instrument readings. The thicker (∼60 nm) anthracene coating did not affect the readings provided by the AMS-SMPS or SP2 instruments but increased the reading of the MAAP instrument by ∼20% and the reading of the PAS by ∼65%. The response of each instrument to the different particle types is discussed in terms of particle morphology and coating material.

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Multi-angle absorption photometry—a new method for the measurement of aerosol light absorption and atmospheric black carbon

Cited by 588 publications

References 30 publications

Black carbon or brown carbon? The nature of light-absorbing carbonaceous aerosols

Black carbon or brown carbon? The nature of light-absorbing carbonaceous aerosols

Mobile monitoring for mapping spatial variation in urban air quality: Development and validation of a methodology based on an extensive dataset

An Inter-Comparison of Instruments Measuring Black Carbon Content of Soot Particles

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