Chemical reactions in the Titan’s troposphere during lightning

Abstract

In the lower troposphere of the Titan the temperature is about 90 K, therefore the chemical production of compounds in the CH 4/N 2 atmosphere is extremely slow. However, atmospheric electricity could provide conditions at which chemical reactions are fast. This paper is based on the assumption that there are lightning discharges in the Titan’s lower atmosphere. The temporal temperature profile of a gas parcel after lightning was calculated at the conditions of 10 km above the Titan’s surface. Using this temperature profile, composition of the after-lightning atmosphere was simulated using a detailed chemical kinetic mechanism consisting of 1829 reactions of 185 species. The main reaction paths leading to the products were investigated. The main products of lighting discharges in the Titan’s atmosphere are H 2, HCN, C 2N 2, C 2H 2, C 2H 4, C 2H 6, NH 3 and H 2CN. The annual production of these compounds was estimated in the Titan’s atmosphere.