The relative column abundances of N2+(A2&Pgr;u, v') ions with v'=0--2 have been examined for a wide range of auroral conditions. Statistically significant changes in the distribution were found to be strongly correlated with auroral ''height indicators'' such as the red-to-blue (R/B) ratio, the intensity ratio I{[NI>3F}/I[N2 + M(0, 0)>, and the effective rotational temperature of selected molecular electronic bands (N2 1 P, N2 + M). The lower-altitude [(R/B)≤0.1> distributions closely approached that observed in the laboratory using a low-pressure N2(X 1&Sgr;g +, v=0) target and a 125-eV electron beam. In sharp contrast, the higher-altitude [(R/B)>1> distributions were characterized by a substantial excess (up to ≈60%) of N2 +(A 2&Pgr;u' v'=1) ions. A plausible explanation of these observations is afforded by the long-standing suggestion that the accidental resonance charge transfer between O+(2D) and N2(X 1&Sgr;g +, v=0) may provide a selective auroral source of N2 +(A 2&Pgr;u' v'=1). ¿ American Geophysical Union 1987