TY  - JOUR
AU  - Dewald, Patrick
AU  - Liebmann, Jonathan M.
AU  - Friedrich, Nils
AU  - Shenolikar, Justin
AU  - Schuladen, Jan
AU  - Rohrer, Franz
AU  - Reimer, David
AU  - Tillmann, Ralf
AU  - Novelli, Anna
AU  - Cho, Changmin
AU  - Xu, Kangming
AU  - Holzinger, Rupert
AU  - Bernard, François
AU  - Zhou, Li
AU  - Mellouki, Wahid
AU  - Brown, Steven S.
AU  - Fuchs, Hendrik
AU  - Lelieveld, Jos
AU  - Crowley, John N.
TI  - Evolution of NO<sub>3</sub> reactivity during the oxidation of isoprene
JO  - Atmospheric chemistry and physics
VL  - 20
IS  - 17
SN  - 1680-7324
CY  - Katlenburg-Lindau
PB  - EGU
M1  - FZJ-2021-01305
SP  - 10459 - 10475
PY  - 2020
AB  - In a series of experiments in an atmospheric simulation chamber (SAPHIR,1 Forschungszentrum Jülich, Germany), NO3 reactivity (kNO3) resulting from the reaction of NO3 with isoprene and stable trace gases formed as products was measured directly using a flow tube reactor coupled to a cavity ring-down spectrometer (FT-CRDS). The experiments were carried out in both dry and humid air with variation of the initial mixing ratios of ozone (50–100 ppbv), isoprene (3–22 ppbv) and NO2 (5–30 ppbv). kNO3 was in excellent agreement with values calculated from the isoprene mixing ratio and the rate coefficient for the reaction of NO3 with isoprene. This result serves to confirm that the FT-CRDS returns accurate values of kNO3 even at elevated NO2 concentrations and to show that reactions of NO3 with stable reaction products like non-radical organic nitrates do not contribute significantly to NO3 reactivity during the oxidation of isoprene. A comparison of kNO3 with NO3 reactivities calculated from NO3 mixing ratios and NO3 production rates suggests that organic peroxy radicals and HO2 account for ∼50 % of NO3 losses. This contradicts predictions based on numerical simulations using the Master Chemical Mechanism (MCM version 3.3.1) unless the rate coefficient for reaction between NO3 and isoprene-derived RO2 is roughly doubled to ∼5×10−12 cm3 molecule−1 s−1.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000569419500001
DO  - DOI:10.5194/acp-20-10459-2020
UR  - https://juser.fz-juelich.de/record/890998
ER  -