Secondary aerosol formation from photochemical aging of aircraft exhaust in a smog chamber
Field experiments were performed to investigate the effects of photo-oxidation on fine particle emissions from an in-use CFM56-2B gas turbine engine mounted on a KC-135 Stratotanker airframe. Emissions were sampled into a portable smog chamber from a rake inlet installed one-meter downstream of the...
| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2011-05-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | http://www.atmos-chem-phys.net/11/4135/2011/acp-11-4135-2011.pdf |
| _version_ | 1819089367903240192 |
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| author | M. A. Miracolo C. J. Hennigan M. Ranjan N. T. Nguyen T. D. Gordon E. M. Lipsky A. A. Presto N. M. Donahue A. L. Robinson |
| author_facet | M. A. Miracolo C. J. Hennigan M. Ranjan N. T. Nguyen T. D. Gordon E. M. Lipsky A. A. Presto N. M. Donahue A. L. Robinson |
| author_sort | M. A. Miracolo |
| collection | DOAJ |
| description | Field experiments were performed to investigate the effects of photo-oxidation on fine particle emissions from an in-use CFM56-2B gas turbine engine mounted on a KC-135 Stratotanker airframe. Emissions were sampled into a portable smog chamber from a rake inlet installed one-meter downstream of the engine exit plane of a parked and chocked aircraft. The chamber was then exposed to sunlight and/or UV lights to initiate photo-oxidation. Separate tests were performed at different engine loads (4, 7, 30, 85 %). Photo-oxidation created substantial secondary particulate matter (PM), greatly exceeding the direct PM emissions at each engine load after an hour or less of aging at typical summertime conditions. After several hours of photo-oxidation, the ratio of secondary-to-primary PM mass was on average 35 ± 4.1, 17 ± 2.5, 60 ± 2.2, and 2.7 ± 1.1 for the 4, 7, 30, and 85 % load experiments, respectively. The composition of secondary PM formed strongly depended on load. At 4 % load, secondary PM was dominated by secondary organic aerosol (SOA). At higher loads, the secondary PM was mainly secondary sulfate. A traditional SOA model that accounts for SOA formation from single-ring aromatics and other volatile organic compounds underpredicts the measured SOA formation by ~60 % at 4 % load and ~40 % at 85 % load. Large amounts of lower-volatiliy organic vapors were measured in the exhaust; they represent a significant pool of SOA precursors that are not included in traditional SOA models. These results underscore the importance of accounting for atmospheric processing when assessing the influence of aircraft emissions on ambient PM levels. Models that do not account for this processing will likely underpredict the contribution of aircraft emissions to local and regional air pollution. |
| first_indexed | 2024-12-21T22:06:49Z |
| format | Article |
| id | doaj.art-378472264ea84b0399660055bd6699b7 |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-12-21T22:06:49Z |
| publishDate | 2011-05-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-378472264ea84b0399660055bd6699b72022-12-21T18:48:41ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242011-05-011194135414710.5194/acp-11-4135-2011Secondary aerosol formation from photochemical aging of aircraft exhaust in a smog chamberM. A. MiracoloC. J. HenniganM. RanjanN. T. NguyenT. D. GordonE. M. LipskyA. A. PrestoN. M. DonahueA. L. RobinsonField experiments were performed to investigate the effects of photo-oxidation on fine particle emissions from an in-use CFM56-2B gas turbine engine mounted on a KC-135 Stratotanker airframe. Emissions were sampled into a portable smog chamber from a rake inlet installed one-meter downstream of the engine exit plane of a parked and chocked aircraft. The chamber was then exposed to sunlight and/or UV lights to initiate photo-oxidation. Separate tests were performed at different engine loads (4, 7, 30, 85 %). Photo-oxidation created substantial secondary particulate matter (PM), greatly exceeding the direct PM emissions at each engine load after an hour or less of aging at typical summertime conditions. After several hours of photo-oxidation, the ratio of secondary-to-primary PM mass was on average 35 ± 4.1, 17 ± 2.5, 60 ± 2.2, and 2.7 ± 1.1 for the 4, 7, 30, and 85 % load experiments, respectively. The composition of secondary PM formed strongly depended on load. At 4 % load, secondary PM was dominated by secondary organic aerosol (SOA). At higher loads, the secondary PM was mainly secondary sulfate. A traditional SOA model that accounts for SOA formation from single-ring aromatics and other volatile organic compounds underpredicts the measured SOA formation by ~60 % at 4 % load and ~40 % at 85 % load. Large amounts of lower-volatiliy organic vapors were measured in the exhaust; they represent a significant pool of SOA precursors that are not included in traditional SOA models. These results underscore the importance of accounting for atmospheric processing when assessing the influence of aircraft emissions on ambient PM levels. Models that do not account for this processing will likely underpredict the contribution of aircraft emissions to local and regional air pollution.http://www.atmos-chem-phys.net/11/4135/2011/acp-11-4135-2011.pdf |
| spellingShingle | M. A. Miracolo C. J. Hennigan M. Ranjan N. T. Nguyen T. D. Gordon E. M. Lipsky A. A. Presto N. M. Donahue A. L. Robinson Secondary aerosol formation from photochemical aging of aircraft exhaust in a smog chamber Atmospheric Chemistry and Physics |
| title | Secondary aerosol formation from photochemical aging of aircraft exhaust in a smog chamber |
| title_full | Secondary aerosol formation from photochemical aging of aircraft exhaust in a smog chamber |
| title_fullStr | Secondary aerosol formation from photochemical aging of aircraft exhaust in a smog chamber |
| title_full_unstemmed | Secondary aerosol formation from photochemical aging of aircraft exhaust in a smog chamber |
| title_short | Secondary aerosol formation from photochemical aging of aircraft exhaust in a smog chamber |
| title_sort | secondary aerosol formation from photochemical aging of aircraft exhaust in a smog chamber |
| url | http://www.atmos-chem-phys.net/11/4135/2011/acp-11-4135-2011.pdf |
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