Poppe, D.FZJ* ; Zimmermann, J. ; Institut für Atmosphärische Chemie (Jülich, 3) - ICG3

1994
Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag Jülich

Report No.: Juel-2938

Abstract: During recent years the importance of isoprene as a reactive biogenic hydrocarbon has been recognized. Since isoprene is poorly represented in RADM2 we have developed an extension by a comprehensive isoprene chemistry. This detailed mechanism (RADM-E) leads to the same results as RADM2 for vanishing concentration of isoprene. The main consequences are the enhanced production of organic nitrates in the course of the isoprene oxidation and the improved conservation of carbon compounds in RADM-E. The balanced C-budget brings about higher concentrations of peroxy radicals and organic peroxides. The formation of organic nitrates leads to smaller amounts of other reactive N-compounds, affecting directly NO" HNO., and PAN, and indirectly uo H 0 '" J~ n Xl 2 2' Qi10 v S' Since RADM-E includes 34 new species and i 12 additional reactions it is not suitable for use in three dimensional transport and chemistry calculation. Therefore a condensed version (RADM-C) was developed with only 8 new species and 19 additional reactions. RADM-C gives approximately the same results as RADM-E, if [NO,] > 0.1 ppb. RADM-E is also compared with the chemical mechanism of Lurmann et al. (1986), which is widely used and includes the chemistry of isoprene in a different manner. in four scenarios, covering typical situations with high impact of isoprene, the chemical mechanisms RADM2 and RADM-C are compared, utilizing a simple 2-boxmodel. Differences of concentrations can exceed 10 percent for 0. and a factor of 2 for HO" peroxides, NO" PAN, and HN03• Carbonyl compounds show even higher differences.

Keyword(s): atmospheric chemistry ; atmospheric circulation ; atmospheric concentration ; atmospheric diffusion ; atmospheric distribution ; atmospheric exchange process ; atmospheric gas ; atmospheric model ; atmospheric monitoring ; atmospheric transport ; isoprene

1. Phytosphäre (ICG-3)
2. Phytosphäre (ICG-3)