Abundances of 15NO2 and H15NO3 in the stratosphere

Using ACE (Atmospheric Chemistry Experiment) satellite data, the volume mixing ratios (VMRs) of stratospheric NO2 and HNO3 and their 15N minor isotopologues have been determined, including global patterns and seasonal trends. Stratospheric & delta;15N values for NO2 and HNO3 have been calculated using VMR data. 14NO2 is relatively enhanced over the winter pole and over the equator in the lower stratosphere but at higher altitudes 15NO2 is enhanced over the winter pole. H15NO3 is relatively enhanced in the lower stratosphere over the summer pole but in the upper stratosphere H14NO3 is enhanced.