A13E-0399
Role of Criegee Intermediates in Formation of Sulfuric Acid at BVOCs-rich Cape Corsica Site
Monday, 14 December 2015
Poster Hall (Moscone South)
Alexandre Kukui1, Sebastien Dusanter2,3, Stéphane Sauvage3, Valerie Gros4, Thierry Bourrianne5, Karine Sellegri6, Jinhe Wang7, Aurélie Colomb6, Jean-Marc Pichon6, Hui Chen7,8, Cerise Kalogridis4, Nora Zannoni4 and Bernard Bonsang4, (1)Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), CNRS, Orléans, France, (2)Indiana University, School of Public and Envrionmental Affairs, Bloomington, IN, United States, (3)Mines Douai, Atmospheric Sciences and Environmental Engineering, Douai, France, (4)Laboratoire des Sciences du Climat et de l'Environnement, Gif-Sur-Yvette Cedex, France, (5)Météo France, CNRS, CNRM-GAME, Toulouse, France, (6)Laboratoire de Météorologie Physique Observatoire de Physique du Globe de Clermont-Ferrand, Aubiere Cedex, France, (7)Fudan Univ, Shanghai Key Lab Atmospher Particle Pollut & Prev, Dept Environm Sci & Engn, Shanghai, China, (8)ICARE, CNRS, Orléans, France
Abstract:
Oxidation of SO2 in reactions with stabilised Criegee Intermediates (sCI) was suggested as an additional source of gaseous sulfuric acid (H2SO4) in the atmosphere, complementary to the conventional H2SO4 formation in reaction of SO2 with OH radicals. Evaluation of the importance of this additional source is complicated due to large uncertainty in the mechanism and rate constants for the reactions of different sCI with SO2, water vapor and other atmospheric species. Here we present an evaluation of the role of sCI in H2SO4 production at remote site on Cape Corsica near the North tip of Corsica Island (Ersa station, Western Mediterranean). In July 2013 comprehensive field observations including gas phase (OH and RO2 radicals, H2SO4, VOCs, NOx, SO2, others) and aerosol measurements were conducted at this site in the frame of ChArMEx project. During the field campaign the site was strongly influenced by local emissions of biogenic volatile compounds (BVOCs), including isoprene and terpenes, forming different sCI in reactions with ozone and, hence, presenting additional source of H2SO4 via sCI+SO2. However, this additional source of H2SO4 at the Ersa site was found to be insignificant. The observed concentrations of H2SO4 were found to be in good agreement with those estimated from the H2SO4 condensation sink and the production of H2SO4 only in the reaction of OH with SO2, without accounting for any additional H2SO4 source. Using the BVOCs observations we present estimation of the upper limit for the rate constants of H2SO4 production via reactions of different sCI with SO2.
