TY  - JOUR
AU  - Novelli, Anna
AU  - Hens, Korbinian
AU  - Tatum Ernest, Cheryl
AU  - Martinez, Monica
AU  - Nölscher, Anke C.
AU  - Sinha, Vinayak
AU  - Paasonen, Pauli
AU  - Petäjä, Tuukka
AU  - Sipilä, Mikko
AU  - Elste, Thomas
AU  - Plass-Dülmer, Christian
AU  - Phillips, Gavin J.
AU  - Kubistin, Dagmar
AU  - Williams, Jonathan
AU  - Vereecken, Luc
AU  - Lelieveld, Jos
AU  - Harder, Hartwig
TI  - Identifying Criegee intermediates as potential oxidants in the troposphere
JO  - Atmospheric chemistry and physics / Discussions
VL  -  
SN  - 1680-7375
CY  - Katlenburg-Lindau
PB  - EGU
M1  - FZJ-2016-05637
SP  -  
PY  - 2016
AB  - We analysed the extensive dataset from the HUMPPA-COPEC 2010 and the HOPE 2012 field campaigns in the boreal forest and rural environments of Finland and Germany, respectively, and estimated the abundance of stabilised Criegee intermediates (SCI) in the lower troposphere. Based on laboratory tests, we propose that the background OH signal observed in our IPI-LIF-FAGE instrument during the afore-mentioned campaigns is caused at least partially by SCI. This hypothesis is based on observed correlations with temperature and with concentrations of unsaturated volatile organic compounds and ozone. The background OH concentration also complements the previously underestimated production rate of sulfuric acid and is consistent with its scavenging through the addition of sulphur dioxide. A central estimate of the SCI concentration of ~ 5 × 104 molecules cm−3 (with an order of magnitude uncertainty) is calculated for the two environments. This implies a very low ambient concentration of SCI, though, over the boreal forest, significant for the conversion of SO2 into H2SO4. The large uncertainties in these calculations, owing to the many unknowns in the chemistry of Criegee intermediates, emphasise the need to better understand these processes and their potential effect on the self-cleaning capacity of the atmosphere.
LB  - PUB:(DE-HGF)16
DO  - DOI:10.5194/acp-2016-919
UR  - https://juser.fz-juelich.de/record/820085
ER  -