Nighttime O(1D) and corresponding Atmospheric Band emission (762 nm) derived from rocket-borne experiment

• Based on common volume rocket-borne measurements of temperature, densities of atomic oxygen and neutral air, we derived O(D-1) nighttime concentrations and corresponding Atmospheric band emission (762 nm). This is one of the first retrievals of the nighttime O(D-1) concentration. Recently, Kalogerakis, Sharma and co-workers have suggested a new production path of O(D-1) based on the reaction of vibrationally excited OH and O. We calculate Atmospheric band volume emission related to the population of O-2(b(1)Sigma(+)(g)) from O(D-1) and compare with total Atmospheric band emissions observed during the same rocket launch. This allows an estimation of the relative contribution of the new Kalogerakis-Sharma mechanism (KSM) to the total Atmospheric band emission. The concentration of O(D-1) due to KSM amounts to several tens cm(-3) with a peak around 95 km. The KSM gives an essential contribution to the total Atmospheric band volume emission (762 nm). Additionally, we illustrate analytically that the expressions for volume emission by the new KSM and the traditional two-step mechanism have similar functional dependences on the atmospheric concentrations of O and O-2. This causes an ambiguity, when interpreting Atmospheric band observations in terms of the one mechanism or the other.

Ämnesord

NATURVETENSKAP  -- Geovetenskap och miljövetenskap (hsv//swe)

NATURAL SCIENCES  -- Earth and Related Environmental Sciences (hsv//eng)

Nyckelord

Atmospheric band emission

Kalogerakis-Sharma mechanism

Two-step mechanism

MLT region

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