CLEPS 1.0: A new protocol for cloud aqueous phase oxidation of VOC mechanisms
- 1Université Clermont Auvergne, CNRS Laboratoire de Météorologie Physique, 63000 Clermont-Ferrand, France
- 2Aix Marseille Université, CNRS, LCE UMR 7376, 13331 Marseille, France
- 3Dipartimento di Chimica, Universita di Torino, V. Giuria 7, 10125 Turin, Italy
- 4Université de Toulouse, UPS, CNRS, Laboratoire d'Aérologie, 31400 Toulouse, France
- 5LISA UMR CNRS 7583, Université Paris Est Créteil et Université Paris Diderot, Paris, France
- 6CEA, DAM, DIF, 91297 Arpajon, France
- anow at: Wolfson Atmospheric Chemistry Laboratories, Department of Chemistry, University of York, Heslington, York, YO10 5DD, UK
- bnow at: Ramboll Environ, 155 rue Louis de Broglie, 13100 Aix-en-Provence, France
Abstract. A new detailed aqueous phase mechanism named the Cloud Explicit Physico-chemical Scheme (CLEPS 1.0) is proposed to describe the oxidation of water soluble organic compounds resulting from isoprene oxidation. It is based on structure activity relationships (SARs) which provide global rate constants together with branching ratios for HO⋅ abstraction and addition on atmospheric organic compounds. The GROMHE SAR allows the evaluation of Henry's law constants for undocumented organic compounds. This new aqueous phase mechanism is coupled with the MCM v3.3.1 gas phase mechanism through a mass transfer scheme between gas phase and aqueous phase. The resulting multiphase mechanism has then been implemented in a model based on the Dynamically Simple Model for Atmospheric Chemical Complexity (DSMACC) using the Kinetic PreProcessor (KPP) that can serve to analyze data from cloud chamber experiments and field campaigns.
The simulation of permanent cloud under low-NOx conditions describes the formation of oxidized monoacids and diacids in the aqueous phase as well as a significant influence on the gas phase chemistry and composition and shows that the aqueous phase reactivity leads to an efficient fragmentation and functionalization of organic compounds.