Comparisons of box model calculations and measurements of formaldehyde from the 1997 North Atlantic Regional Experiment

Frost, G. J.; Fried, Alan; Lee, Y. N.; Wert, B.; Henry, Bruce; Drummond, J. R.; Evans, M. J.; Fehsenfeld, F. C.; Goldan, P. D.; Holloway, J. S.; Hübler, G.; Jakoubek, R.; Jobson, T.; Knapp, Kenneth R.; Kuster, W. C.; Roberts, J. M.; Rudolph, J.; Ryerson, Thomas B.; Stohl, Andreas; Stroud, Craig; Sueper, D.; Trainer, M.; Williams, Jonathan

doi:10.1029/2001jd000896

Cited by 49 publications

(77 citation statements)

References 38 publications

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“…The slope, which has been used frequently to initialise acetone mixing ratios in model calculations, is 6.1 ppt v acetone/ppb v CO (e.g. McKeen et al, 1997;Keim et al, 1999;Frost et al, 2002), and has been observed in the stratosphere during PEM-WEST B. This slope is based on data published by Singh et al (1997), however, the linear relation is described by McKeen et al (1997).…”

Section: Comparison With Literature Valuesmentioning

confidence: 85%

“…In global models, emissions of acetone are mostly explicitly described, whereas in box model studies the model is generally constrained to measurements. Since acetone measurements are not always available, the correlation between acetone and CO is often used for model initialisation (McKeen et al, 1997;Keim et al, 1999;Frost et al, 2002). This paper deals with the acetone-CO correlation observed during different aircraft measurement campaigns.…”

Section: European Geosciences Union 2003mentioning

confidence: 99%

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On the relationship between acetone and carbon monoxide in different air masses

et al. 2003

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Abstract. Carbon monoxide and acetone measurements are presented for five aircraft measurement campaigns at midlatitudes, polar and tropical regions in the northern hemisphere. Throughout all campaigns, free tropospheric air masses, which were influenced by anthropogenic emissions, showed a similar linear relation between acetone and CO, with a slope of 21-25 ppt v acetone/ppb v CO. Measurements in the anthropogenically influenced marine boundary layer revealed a slope of 13-16 ppt v acetone/ppb v CO. The different slopes observed in the marine boundary layer and the free troposphere indicate that acetone is emitted by the ocean in relatively clean air masses and taken up by the ocean in polluted air masses. In the lowermost stratosphere, a good correlation between acetone and CO was observed as well, however, with a much smaller slope (∼5 ppt v acetone/ppb v CO) compared to the troposphere. This is caused by the longer photochemical lifetime of CO compared to acetone in the lower stratosphere, due to the increasing photolytic loss of acetone and the decreasing OH concentration with altitude. No significant correlation between acetone and CO was observed over the tropical rain forest due to the large direct and indirect biogenic emissions of acetone.The common slopes of the linear acetone-CO relation in various layers of the atmosphere, during five field experiments, makes them useful for model calculations. Often a single observation of the acetone-CO correlation, determined from stratospheric measurements, has been used in box model applications. This study shows that different slopes have to be considered for marine boundary layer, free tropospheric and stratospheric air masses, and that the acetone-CO relation cannot be used for air masses which are strongly influenced by biogenic emissions.Correspondence to: M. de Reus

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Section: Comparison With Literature Valuesmentioning

confidence: 85%

Section: European Geosciences Union 2003mentioning

confidence: 99%

On the relationship between acetone and carbon monoxide in different air masses

et al. 2003

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“…While direct emissions from fossil fuel combustion, biomass burning, and also automotive exhaust contribute significantly to the burden of atmospheric CH 2 O (Carlier et al, 1986;Garcia et al, 2005), in situ production of CH 2 O by photochemical oxidation of volatile organic compounds appears to be the dominant source on a global scale (Carlier et al, 1986;Warneck, 1999). In remote oceanic areas (Wagner et al, 2002;Weller et al, 2000), in the free troposphere (Frost et al, 2002), and in the stratosphere, only the photochemical oxidation of CH 4 serves as the major source. Apart from the importance of the rather simple CH 2 O molecule in the Earth's atmosphere and far beyond, it is also subject to fundamental research regarding for instance the exact processes during its photolysis (e.g., Moore and Weisshaar, 1983;Townsend et al, 2004;Troe, 2007).…”

Section: Introductionmentioning

confidence: 99%

Hydrogen isotope fractionation in the photolysis of formaldehyde

2008

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Abstract. Experiments investigating the isotopic fractionation in the formation of H 2 by the photolysis of CH 2 O under tropospheric conditions are reported and discussed. The deuterium (D) depletion in the H 2 produced is 500(±20)‰ with respect to the parent CH 2 O. We also observed that complete photolysis of CH 2 O under atmospheric conditions produces H 2 that has virtually the same isotope ratio as that of the parent CH 2 O. These findings imply that there must be a very strong concomitant isotopic enrichment in the radical channel (CH 2 O+hν→CHO+H) as compared to the molecular channel (CH 2 O+hν→H 2 +CO) of the photolysis of CH 2 O in order to balance the relatively small isotopic fractionation in the competing reaction of CH 2 O with OH. Using a 1-box photochemistry model we calculated the isotopic fractionation factor for the radical channel to be 0.22(±0.08), which is equivalent to a 780(±80)‰ enrichment in D of the remaining CH 2 O. When CH 2 O is in photochemical steady state, the isotope ratio of the H 2 produced is determined not only by the isotopic fractionation occurring during the photolytical production of H 2 (α m ) but also by overall fractionation for the removal processes of CH 2 O (α f ), and is represented by the ratio of α m /α f . Applying the isotopic fractionation factors relevant to CH 2 O photolysis obtained in the present study to the troposphere, the ratio of α m /α f varies from ∼0.8 to ∼1.2 depending on the fraction of CH 2 O that reacts with OH and that produces H 2 . This range of α m /α f can render the H 2 produced from the photochemical oxidation of CH 4 to be enriched in D (with respect to the original CH 4 ) by the factor of 1.2-1.3 as anticipated in the literature.

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“…There have been several recent formaldehyde measurement/model comparisons in the North Atlantic environment (Weller et al, 2000;Frost et al, 2002; in which all under predict measured formaldehyde concentrations to some degree. Weller et al compared measured average formaldehyde concentrations of 580±160 pptv from a North Atlantic cruise with calculated values based on a box model.…”

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confidence: 99%

Ambient formaldehyde measurements made at a remote marine boundary layer site during the NAMBLEX campaign – a comparison of data from chromatographic and modified Hantzsch techniques

et al. 2006

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Abstract. Ambient formaldehyde concentrations are reported from the North Atlantic Marine Boundary Layer Experiment (NAMBLEX) campaign at Mace Head on the west coast of Eire during August 2002. The results from two techniques, using direct determination via gas chromatography and the Hantzsch technique, show similar trends but a significant off set in concentrations. For westerly air flows characteristic of the marine boundary layer, formaldehyde concentrations from the gas chromatographic and Hantzsch technique ranged from 0.78-1.15 ppb and 0.13-0.43 ppb, respectively. Possible reasons for the discrepancy have been investigated and are discussed, however, no satisfactory explanation has yet been found. In a subsequent laboratory intercomparison the two techniques were in good agreement.The observed concentrations have been compared with previous formaldehyde measurements in the North Atlantic marine boundary layer and with other measurements from the NAMBLEX campaign. The measurements from the Hantzsch technique and the GC results lie at the lower and upper ends respectively of previous measurements. In contrast to some previous measurements, both techniques show distinct diurnal profiles with day maxima and with an amplitude of approximately 0.15 ppb. Strong correlations were observed with ethanal concentrations measured during NAM-BLEX and the ratio of ethanal to formaldehyde determined by the gas chromatographic technique is in good agreement with previous measurements.Some simple box modelling has been undertaken to investigate possible sources of formaldehyde. Such models are not able to predict absolute formaldehyde concentrations as they do not include transport processes, but the results show Correspondence to: P. W. Seakins (p.w.seakins@chem.leeds.ac.uk) that oxygenated VOCs such as ethanal and methanol are very significant sources of formaldehyde in the air masses reaching Mace Head.

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Comparisons of box model calculations and measurements of formaldehyde from the 1997 North Atlantic Regional Experiment

Cited by 49 publications

References 38 publications

On the relationship between acetone and carbon monoxide in different air masses

On the relationship between acetone and carbon monoxide in different air masses

Hydrogen isotope fractionation in the photolysis of formaldehyde

Ambient formaldehyde measurements made at a remote marine boundary layer site during the NAMBLEX campaign – a comparison of data from chromatographic and modified Hantzsch techniques

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