Rocketborne interferometer measurement of infrared auroral spectra

Abstract

Short- and mid-wavelength infrared auroral spectra in the range from 1300 to 4000 cm −1 (7.7 to 2.5 μm) have been obtained with a rocketborne. cryogenic, field-widened interferometer at an unapodized resolution of 1.08 cm −1. Spectra were obtained at altitudes ranging from 89 to 135 km with a NESR of 63 R per cm −1 (2 × 10 −13 W cm −2 sr −1 cm). Synthetic spectra provided identification of many prominent molecular bands in the region, including the Δυ = 1 sequence of nitric oxide (NO) near 5.4 μm, the carbon monoxide (CO) fundamental near 4.7 μm, strong emissions due to carbon dioxide (CO 2) which overlap the weak Δυ = 1 sequence of ionized nitric oxide (NO + ) near 4.3 μm, and the Δυ = 1 sequence of hydroxyl (OH) in the 2.8 μm region of the spectra. In addition, several band heads from the NO Δυ = 1 sequence have been identified and these suggest a highly non-thermal production source of the high lying rotational levels of NO. The data, synthetic spectra, absolute intensities, the rotational temperatures of many of the dominant molecular band emitters are presented and are compared to earlier, low resolution results.