Mass spectrometric contributions to problems related to the chemistry of atmospheres

Recent mass spectrometric studies of species and processes relevant to the chemistry of atmospheres are reported. New species have been detected, including HO3; a stratospheric reservoir of OH radicals; the [H2O+O2-] charge transfer complex, central to the atmospheric photonucleation theory; and the OSOSO oxide and its cation, likely present in the Io's atmosphere, As to ionic processes, a new route to tropospheric N2O in air ionized by lightning and coronas is reported, as well as the complex chemistry promoted by ionization of ozone/freon and ozone/carbonyl sulfide mixtures and the formation of O-5(+), relevant to the problem of O-18 excess in stratospheric ozone