Chamber Studies of NO3 reactivity during the oxidation of isoprene
- 1Atmospheric Chemistry Department, Max Planck Institut für Chemie, Mainz, Germany (patrick.dewald@mpic.de)
- 2Institute of Energy and Climate Research, IEK-8: Troposphere, Forschungszentrum Jülich GmbH, Jülich, Germany
- 3Institute for Marine and Atmospheric Research, IMAU, Utrecht University, Utrecht, Netherlands
- 4Institut de Combustion, Aérothermique, Réactivité et Environnement (ICARE), CNRS (UPR 3021)/OSUC, Orléans Cedex 2, France
- 5Chemical Science Division, NOAA Earth System Research Laboratory, Boulder, CO, USA
Isoprene is the major volatile organic compound that is released into the environment via biogenic emissions and its oxidation can result in formation of secondary organic aerosol (SOA). Although isoprene emission occurs mainly at daytime, it can accumulate at nighttime and be oxidized by the nitrate radical (NO3) to form organic nitrates that can partition to the particle phase. A detailed understanding of the reaction between isoprene and NO3 is thus required to predict its role in e.g. NOX lifetimes and SOA formation.
The reaction between NO3 and isoprene was investigated under varying experimental conditions (high or low RO2/HO2, temperature, humidity, seed aerosols) during the NO3ISOP campaign at the atmospheric simulation chamber SAPHIR of the research centre in Jülich (Germany). Direct measurement of the NO3 reactivity was carried out with means of a flowtube coupled to a cavity-ring-down spectroscopy (FT-CRDS) setup which enabled the evolution of the NO3 lifetime during the isoprene oxidation process to be monitored.
By comparing direct NO3 reactivity measurements with those calculated from VOC mixing ratios and those calculated from a stationary-state analysis we identify the contributions of isoprene, secondary oxidation products and peroxy radicals to NO3 losses.
How to cite: Dewald, P., Shenolikar, J., Friedrich, N., Rohrer, F., Tillmann, R., Reimer, D., Xu, K., Holzinger, R., Bernard, F., Zhou, L., Brown, S., Fuchs, H., and Crowley, J.: Chamber Studies of NO3 reactivity during the oxidation of isoprene, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-4597, https://doi.org/10.5194/egusphere-egu2020-4597, 2020.
