Terpenoids in the atmosphere

Terpenoids (terpenes and their oxygenated derivatives) are common tropospheric species. Information concerning the terpenoids and assessing their importance in atmospheric processes is sparse and widely distributed, however. This review presents chemical structure, physical property, and source information for 45 terpenoids known to be emitted into the atmosphere. Rate constants for the reactions of the terpenoids with atmospheric scavengers are presented, and typical terpenoid lifetimes are derived. Chemical product studies are used to derive plausible reaction mechanisms for selected acyclic, monocyclic, and bicyclic terpenes. The atmospheric cycle of the terpenoids is discussed, and it is concluded that inadequate information currently precludes quantitative assessments of the relative impact of terpenoids on local, regional, and global atmospheric processes.