ENERGETIC PARTICLE-INDUCED ENHANCEMENTS OF STRATOSPHERIC NITRIC-ACID

Inclusion of complete ion chemistry in the calculation of minor specie s production during energetic particle deposition events leads to sign ificant enhancement in the calculated nitric acid concentration during precipitation. An ionization rate of 1.2 x 10(3) cm-3 s-1 imposed for 1 day increases HNO3 from 3 x 10(5) to 6 x 10(7) cm-3 at 50 km. With an ionization rate of 600 cm-3 s-1, the maximum HNO3 is 3 x 10(7) cm-3 . Calculations which neglect negative ions predict that nitric acid wi ll fall during precipitation events. The decay time for converting HNO 3 into odd nitrogen and hydrogen is more than 1 day for equinoctial pe riods at 70-degrees latitude. Examination of nitric acid data should y ield important information on the magnitude and frequency of charged p article events.