Rocket‐borne spectroscopic measurements in the ultraviolet aurora: The Lyman‐Birge‐Hopfield bands

Ultraviolet emissions from Earth's aurora were observed at wavelengths between 1675 and 2075 Å by a sounding rocket payload launched at Churchill, Canada, on March 28, 1980. The emissions from the Lyman‐Birge‐Hopfield (LBH) and Vegard‐Kaplan (VK) bands of N2 were observed and analyzed to determine the relative populations of the υ′ = 0–6 levels of the a¹πg state and the υ′ = 4, 6, 7, and 8 levels of the A³Σg+ state respectively. The relative population of higher vibrational levels of the A³Σg+ state are consistant with direct excitation and cascade. The relative populations of the vibrational levels of the a¹πg state peak at υ′ = 2. Such a distribution has not been observed previously in the aurora.