In situ measurements of stratospheric nitric oxide using a balloon-borne chemiluminescent instrument

Nitric oxide mixing ratios have been measured under high sun conditions in the stratosphere over the altitude range 17–30.5 km during four balloon flights launched from New Mexico. Experimental evidence is also presented to confirm that no serious sampling errors were encountered either from contamination of the sampled air or from removal of nitric oxide in the inlet to the instrument.