1 research outputs found
Gas-Phase Reactions of Isoprene and Its Major Oxidation Products
Isoprene carries approximately half
of the flux of non-methane
volatile organic carbon emitted to the atmosphere by the biosphere.
Accurate representation of its oxidation rate and products is essential
for quantifying its influence on the abundance of the hydroxyl radical
(OH), nitrogen oxide free radicals (NO<sub><i>x</i></sub>), ozone (O<sub>3</sub>), and, via the formation of highly oxygenated
compounds, aerosol. We present a review of recent laboratory and theoretical
studies of the oxidation pathways of isoprene initiated by addition
of OH, O<sub>3</sub>, the nitrate radical (NO<sub>3</sub>), and the
chlorine atom. From this review, a recommendation for a nearly complete
gas-phase oxidation mechanism of isoprene and its major products is
developed. The mechanism is compiled with the aims of providing an
accurate representation of the flow of carbon while allowing quantification
of the impact of isoprene emissions on HO<sub><i>x</i></sub> and NO<sub><i>x</i></sub> free radical concentrations
and of the yields of products known to be involved in condensed-phase
processes. Finally, a simplified (reduced) mechanism is developed
for use in chemical transport models that retains the essential chemistry
required to accurately simulate isoprene oxidation under conditions
where it occurs in the atmosphereî—¸above forested regions remote
from large NO<sub><i>x</i></sub> emissions