Nitric oxide measurements in the equatorial Pacific region

Surface nitric oxide mixing ratios were measured in the equatorial Pacific region using a chemiluminescent detector. The average NO mixing ratio was about 4 pptv during noontime conditions for nine days of measurements. These NO mixing ratios, which are much lower than any previously reported, imply that the O3 production rate due to CO and CH4 oxidation may be less than previously believed. They also imply smaller OH/HO ratios as a consequence of the lower HO2 to OH² conversion by NO.