What is the role of NOx in ozone depletion?

NOx is the byproduct of water vapor blocking one path of ozone production. An oxygen atom is temporarily stored in an unstable state on a nitrogen molecule (N2O*). Encountering a water molecule stabilizes the NOx. NOx does not itself decay ozone, but acts as a "getter" for water vapor (further protecting ozone). NOx is like the dead body for a stillborn ozone molecule.