Lightning-induced heating of the nighttime D region leads to the excitation of a number of lines of O, O2, N2, O2+, and N2+, at intensities of 10--109 Rayleighs (R) for vertical observations. For example, the 5577 ¿ emission from O has intensity ~60 R lasting for ~350 ms while the 1st and 2nd positive bands of N2 are at ~109 R but last only ~50 &mgr;s. ¿ American Geophysical Union 1992