C<sub>3</sub>-C<sub>5</sub> alkanes in the atmosphere: concentration, seasonal cycle and contribution to the atmospheric budgets of acetone and acetaldehyde
Author:
Pozzer A.,Pollmann J.,Taraborrelli D.,Jöckel P.,Helmig D.,Tans P.,Hueber J.,Lelieveld J.
Abstract
Abstract. The atmospheric chemistry of C3-C5 alkanes has been incorporated in the atmospheric-chemistry general circulation model EMAC. Model output is compared with observations from the NOAA/ESRL GMD cooperative air sampling network. A new series of measurements is used to evaluate the model in representing C3-C5 alkanes (i.e. propane, isobutane, butane, isopentane and pentane). While the representation of propane is within the measurement standard deviation, some deviations are found for the other tracers. The model is able to reproduce the main features of the C3-C5 alkanes (e.g., seasonality). However, in the Northern Hemisphere during winter the mixing ratios of these alkanes are generally overestimated. Conversely, the model shows an underestimation in the Southern Hemisphere. Moreover, only for iso-pentane there is a net overestimation of the mixing ratios, while for the other alkanes, the results are at the higher end of the measurement range. The effects of the C3-C5 alkanes to atmospheric acetone and acetaldehyde are quantified. The total amount of acetone produced by propane, isobutane and isopentane oxidation is 11.6 Tg/yr, 4.2 Tg/yr and 5.8 Tg/yr, respectively. These chemical sources are largely controlled by the reaction with OH, while the reactions with NO3 and Cl contribute only to a little extent. Moreover, 3.1, 4.5, 1.9 and 6.7 Tg/yr of acetaldehyde are formed from the oxidation of propane, butane, pentane and isopentane, respectively. Also for acetaldehyde, the formation is controlled by the reaction of alkanes with OH. However, since isopentane is generally overestimated, its contribution to the production of these oxygenated compounds represents an upper limit.
Publisher
Copernicus GmbH
Reference83 articles.
1. Andreae, M O. and Merlet, P.: Emission of trace gases and aerosols from biomass burning, Global Biogeochem. Cy., 15, 955–966, 2001. 2. Arnold, S R., Chipperfield, M P., and Blitz, M.: A three-dimensional model study of the effect of new temperature-dependent quantum yields for acetone photolysis, Geophys. Res. Lett., 110, D22305, https://doi.org/10.1029/2005JD005998, 2005. 3. Atkinson, R.: Atmospheric chemistry of VOCs and NOx, Atmos. Environ., 34, 2063–2101, 2000. 4. Bey, I., Jacob, D J., Yantosca, R M., Logan, J A., Field, B D., Fiore, A M., Li, Q., Liu, H Y., Mickley, L J., and Schultz, M G.: Global modeling of tropospheric chemistry with assimilated meteorology: Model description and evaluation, J. Geophys. Res., 106, 23073–23095, 2001. 5. Blake, D. and Rowland, S.: Urban leakage of liquefied petroleum gas and its impact on Mexico City air quality, Science, 269, 953–956, 1995.
Cited by
1 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献
|
|