Towards a reduction of the bimolecular reaction model for Titan ionosphere
Résumé
The aim of this paper is to highlight the skeletal chemistry responsible for the richionospheric chemistry observed in Titan's atmosphere. The present database is representedby about 700 ion–molecule reactions, which are not all important to describe the system. Ourcriterion to reduce the list of reactions is to reproduce a reference mass spectrum within itsuncertainties. This reference mass spectrum is obtained with the complete reaction databaseand with neutral densities optimized for the INMS mass spectrum measured at 1200 km duringthe T5 flyby. We compared two mechanism reduction methods, brute force screening and globalsensitivity analysis. The analysis of the residual scheme with only 35 bimolecular reactionshighlights several patterns, concerning in particular ionic growth processes and introductionof nitrogen to the ionic species.