Formaldehyde over the eastern Mediterranean during MINOS: Comparison of airborne in-situ measurements with 3D-model results
Formaldehyde (HCHO) is an important intermediate product in the photochemical degradation of methane and non-methane volatile organic compounds. In August 2001, airborne formaldehyde measurements based on the Hantzsch reaction technique were performed during the Mediterranean INtensive Oxidant Study...
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ftdoajarticles:oai:doaj.org/article:e567566b43c84e8090148e7860f0ef8c 2023-05-15T17:35:57+02:00 Formaldehyde over the eastern Mediterranean during MINOS: Comparison of airborne in-situ measurements with 3D-model results R. Kormann H. Fischer M. de Reus M. Lawrence Ch. Brühl R. von Kuhlmann R. Holzinger J. Williams J. Lelieveld C. Warneke J. de Gouw J. Heland H. Ziereis H. Schlager 2003-01-01T00:00:00Z https://doaj.org/article/e567566b43c84e8090148e7860f0ef8c EN eng Copernicus Publications http://www.atmos-chem-phys.net/3/851/2003/acp-3-851-2003.pdf https://doaj.org/toc/1680-7316 https://doaj.org/toc/1680-7324 1680-7316 1680-7324 https://doaj.org/article/e567566b43c84e8090148e7860f0ef8c Atmospheric Chemistry and Physics, Vol 3, Iss 3, Pp 851-861 (2003) Physics QC1-999 Chemistry QD1-999 article 2003 ftdoajarticles 2022-12-31T06:25:08Z Formaldehyde (HCHO) is an important intermediate product in the photochemical degradation of methane and non-methane volatile organic compounds. In August 2001, airborne formaldehyde measurements based on the Hantzsch reaction technique were performed during the Mediterranean INtensive Oxidant Study, MINOS. The detection limit of the instrument was 42 pptv (1 s ) at a time resolution of 180 s (10-90%). The overall uncertainty of the HCHO measurements was 30% at a mixing ratio of 300 pptv. In the marine boundary layer over the eastern Mediterranean Sea average HCHO concentrations were of the order of 1500 pptv, in reasonable agreement with results from a three-dimensional global chemical transport model of the lower atmosphere including non-methane volatile organic compound (NMVOC) chemistry. Above the boundary layer HCHO mixing ratios decreased with increasing altitude to a minimum level of 250 pptv at about 7 km. At higher altitudes (above 7 km) HCHO levels showed a strong dependency on the airmass origin. In airmasses from the North Atlantic/North American area HCHO levels were of the order of 300 pptv, a factor of 6 higher than values predicted by the model. Even higher HCHO levels, increasing to values of the order of 600 pptv at 11 km altitude, were observed in easterlies transporting air affected by the Indian monsoon outflow towards the Mediterranean basin. Only a small part (~30 pptv) of the large discrepancy between the model results and the measurements of HCHO in the free troposphere could be explained by a strong underestimation of the upper tropospheric acetone concentration by up to a factor of ten by the 3D-model. Therefore, the measurement-model difference in the upper troposphere remains unresolved, while the observed dependency of HCHO on airmass origin might indicate that unknown, relatively long-lived NMVOCs - or their reaction intermediates - associated with biomass burning are at least partially responsible for the observed discrepancies. Article in Journal/Newspaper North Atlantic Directory of Open Access Journals: DOAJ Articles Indian |
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language |
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topic |
Physics QC1-999 Chemistry QD1-999 |
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Physics QC1-999 Chemistry QD1-999 R. Kormann H. Fischer M. de Reus M. Lawrence Ch. Brühl R. von Kuhlmann R. Holzinger J. Williams J. Lelieveld C. Warneke J. de Gouw J. Heland H. Ziereis H. Schlager Formaldehyde over the eastern Mediterranean during MINOS: Comparison of airborne in-situ measurements with 3D-model results |
topic_facet |
Physics QC1-999 Chemistry QD1-999 |
description |
Formaldehyde (HCHO) is an important intermediate product in the photochemical degradation of methane and non-methane volatile organic compounds. In August 2001, airborne formaldehyde measurements based on the Hantzsch reaction technique were performed during the Mediterranean INtensive Oxidant Study, MINOS. The detection limit of the instrument was 42 pptv (1 s ) at a time resolution of 180 s (10-90%). The overall uncertainty of the HCHO measurements was 30% at a mixing ratio of 300 pptv. In the marine boundary layer over the eastern Mediterranean Sea average HCHO concentrations were of the order of 1500 pptv, in reasonable agreement with results from a three-dimensional global chemical transport model of the lower atmosphere including non-methane volatile organic compound (NMVOC) chemistry. Above the boundary layer HCHO mixing ratios decreased with increasing altitude to a minimum level of 250 pptv at about 7 km. At higher altitudes (above 7 km) HCHO levels showed a strong dependency on the airmass origin. In airmasses from the North Atlantic/North American area HCHO levels were of the order of 300 pptv, a factor of 6 higher than values predicted by the model. Even higher HCHO levels, increasing to values of the order of 600 pptv at 11 km altitude, were observed in easterlies transporting air affected by the Indian monsoon outflow towards the Mediterranean basin. Only a small part (~30 pptv) of the large discrepancy between the model results and the measurements of HCHO in the free troposphere could be explained by a strong underestimation of the upper tropospheric acetone concentration by up to a factor of ten by the 3D-model. Therefore, the measurement-model difference in the upper troposphere remains unresolved, while the observed dependency of HCHO on airmass origin might indicate that unknown, relatively long-lived NMVOCs - or their reaction intermediates - associated with biomass burning are at least partially responsible for the observed discrepancies. |
format |
Article in Journal/Newspaper |
author |
R. Kormann H. Fischer M. de Reus M. Lawrence Ch. Brühl R. von Kuhlmann R. Holzinger J. Williams J. Lelieveld C. Warneke J. de Gouw J. Heland H. Ziereis H. Schlager |
author_facet |
R. Kormann H. Fischer M. de Reus M. Lawrence Ch. Brühl R. von Kuhlmann R. Holzinger J. Williams J. Lelieveld C. Warneke J. de Gouw J. Heland H. Ziereis H. Schlager |
author_sort |
R. Kormann |
title |
Formaldehyde over the eastern Mediterranean during MINOS: Comparison of airborne in-situ measurements with 3D-model results |
title_short |
Formaldehyde over the eastern Mediterranean during MINOS: Comparison of airborne in-situ measurements with 3D-model results |
title_full |
Formaldehyde over the eastern Mediterranean during MINOS: Comparison of airborne in-situ measurements with 3D-model results |
title_fullStr |
Formaldehyde over the eastern Mediterranean during MINOS: Comparison of airborne in-situ measurements with 3D-model results |
title_full_unstemmed |
Formaldehyde over the eastern Mediterranean during MINOS: Comparison of airborne in-situ measurements with 3D-model results |
title_sort |
formaldehyde over the eastern mediterranean during minos: comparison of airborne in-situ measurements with 3d-model results |
publisher |
Copernicus Publications |
publishDate |
2003 |
url |
https://doaj.org/article/e567566b43c84e8090148e7860f0ef8c |
geographic |
Indian |
geographic_facet |
Indian |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Atmospheric Chemistry and Physics, Vol 3, Iss 3, Pp 851-861 (2003) |
op_relation |
http://www.atmos-chem-phys.net/3/851/2003/acp-3-851-2003.pdf https://doaj.org/toc/1680-7316 https://doaj.org/toc/1680-7324 1680-7316 1680-7324 https://doaj.org/article/e567566b43c84e8090148e7860f0ef8c |
_version_ |
1766135269621235712 |