Quenching of N(2P) by atomic O has been included in the calculations used to estimate changes in mean emission heights of auroral forms previously studied by Vallance Jones and Gattinger (1978). Recent estimates of the production efficiency for N(2P) in electron impact dissociation of N2 permit a cross check on the estimated height from the intensity of the 1.04-&mgr;m [N I> multiplet. Satisfactory agreement is obtained if the atomic O concentration in the 110- to 120-km region was about half that of the Jacchia (1971) model for a N(2P) -O quenching rate coefficient of 10-11 cm3 s-1.