The Radiant Output of Grenade Glow Clouds in the Lower Thermosphere

Abstract

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.

Further Spectral Observations of Grenade Glow Clouds in the Lower Thermosphere

“…The present paper discusses the spectral observations made with a specially built grating spectroradiometer (Johnson 1965). The results of other measurements in the same series of experiments are presented elsewhere (Johnson et al 1967).…”

Ambient and Modified Atmospheric Ion Chemistry: From Top to Bottom

“…The first step must be oxidation of the TMA to form, presumably, AlO, AlO 2 , or a mixture of the two, although the exact reaction is not known. A commonly accepted mechanism for aluminum chemiluminescence is a radiative recombination reaction of AlO with O to form electronically excited AlO 2: ,,, Because the emission is broadband, it is difficult to identify AlO 2 as the emitting species with certainty, but this identification is consistent with many laboratory investigations . A catalytic cycle involving O atoms can regenerate AlO and may be an additional source of chemiluminescence if the AlO involved is formed in an excited state …”

“…230 A catalytic cycle involving O atoms can regenerate AlO and may be an additional source of chemiluminescence if the AlO involved is formed in an excited state. 229 Gole and Kolb 230 showed that the radiative recombination reaction is likely too slow, by perhaps 4 orders of magnitude, to explain the atmospheric results. They proposed instead either (1) that AlO* is the source of the observed chemiluminescence through Al 2 + O → AlO* + Al or (2) that an aluminum−water adduct, HAlOH, causes the emissions through Al + H 2 O → HAlOH*.…”