Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published November 15, 1994 | Published
Journal Article Open

The distribution of hydrogen, nitrogen, and chlorine radicals in the lower stratosphere: Implications for changes in O_3 due to emission of NO_y from supersonic aircraft


In situ measurements of hydrogen, nitrogen, and chlorine radicals obtained in the lower stratosphere during SPADE are compared to results from a photochemical model that assimilates measurements of radical precursors and environmental conditions. Models allowing for heterogeneous hydrolysis of N_2O_5 agree well with measured concentrations of NO and ClO, but concentrations of HO_2 and OH are underestimated by 10 to 25%, concentrations of NO_2 are overestimated by 10 to 30%, and concentrations of HCl are overestimated by a factor of 2. Discrepancies for [OH] and [HO_2] are reduced if we allow for higher yields of O(^1D) from O_3 photolysis and for heterogeneous production of HNO_2. The data suggest more efficient catalytic removal of O_3 by hydrogen and halogen radicals relative to nitrogen oxide radicals than predicted by models using recommended rates and cross sections. Increases in [O_3] in the lower stratosphere may be larger in response to inputs of NO_y from supersonic aircraft than estimated by current assessment models.

Additional Information

© 1994 American Geophysical Union. Received: May 19, 1994; revised: August 29, 1994; accepted: September 7, 1994. Paper number 94GL02781. This work was supported by NASA grants NAG2-731, NAGW-1230, NAS1-19955 and NSF grant ATM-89-21119 to Harvard University. We thank J. Herman and the GSFC processing team for providing data from TOMS and P. Newman and R. Nagatani for providing data from NMC.

Attached Files

Published - grl7983.pdf


Files (460.4 kB)
Name Size Download all
460.4 kB Preview Download

Additional details

August 22, 2023
August 22, 2023