SummaryThe spectral energy distribution is given for the glow clouds resulting from the explosion of aluminized grenades in the range of altitude from 100 to 200 km. At night, over much of the spectral range from 300 to 800 nm, the spectrum is a continuum very similar to that of a black body at 4000-5000 o K. At twilight, emissions resulting from resonant scattering of sunlight by AI, K, Ba, Na, and AIO are superimposed on, and dominate, the continuum.

SummaryRecords of the behaviour of aluminized grenade glow clouds at twilight and at night were obtained using cameras and photometers. From these records the radiance, radiant p~wer, and radiant energy have been deduced for the altitude range 100-200 km. The twilight observations show that the absorption cross section of aluminium monoxide is about 3 X lO-14 cm2• From the night-time results it is concluded that the glow probably arises from a chemiluminescent reaction with atomic oxygen. A set of reactions consistent with the observations above 120 km altitude is AI02 +O -+ AIO+02, AIO+O -+ AI02+hv, AIO+O -+ AI+02, with the rate constants being 5 X 10-12, 1 X 10-13, and 4 X 10-13 cm3 molecule-1 sec-1 respectively.