Intensity variation of O i λ5577 Å line of atomic oxygen at allahabad during morning and evening twilight
Intensity variation of O i green line observed at Allahabad (25°32' N, 81°53' E) by a laboratorymade photometer has been reported here for the period January 1988 to December 1988. During the summer period of observation, slight enhancement in the intensity of evening and morning twilight emission is observed for a short duration of 4 min. However, winter observations show less pronounced enhancement in the intensity of evening twilight, while it does not occur during morning twilight. These observations are closely in agreement with those of Schaffer (1975).