It is argued that dissociative photoionization of N2 by solar ultraviolet radiation at wavelengths shorter than 329 ¿ is a large source of atmospheric N+(5S02) ions which radiate at 2143.6 ¿ and 2139.7 ¿. Calculations of the daytime production of N+(5S02) ions are carried out. The band pass of the instrument used to measure the intensity of the NO &ggr; band at 2150 ¿ contains the N+ emission wavelengths and we suggest that the NO densities at high altitudes may be affected.