First flight of the mid-infrared limb-imaging interferometer GLORIA on a stratospheric balloon

GLORIA (Gimballed Limb Observer for Radiance Imaging of the Atmosphere) is a limb-imaging Fourier-Transform spectrometer (iFTS) providing radiances of the thermal infrared emission of atmospheric species. The nominal wavelength range is from 780 to1400 cm^-1 with a spectral sampling of 0.0625 cm^-1. GLORIA-B is an adaption of the airborne GLORIA instrument to stratospheric balloon platforms. It has performed its first flight from ESRANGE/Northern Sweden in August 2021 during the KLIMAT 2021 campaign in the framework of the EU Research Infrastructure HEMERA.

The maiden flight of GLORIA-B has proven its technical qualification and has provided a first imaging hyperspectral limb-emission dataset from 5 to 36 km altitude. Scientific objectives are, amongst others, the observation of the evolution of the upper tropospheric and stratospheric chlorine and nitrogen budget/family partitioning in a changing climate in combination with the set of 20 MIPAS-B (Michelson Interferometer for Passive Atmospheric sounding-balloon) flights since the mid-1990ies, the observation of photochemically active trace gases during sunset and sunrise, as well as the quantification of pollution of the Arctic upper troposphere/lower stratosphere, e.g. through forest fires.

In this contribution we will demonstrate the performance of GLORIA-B with regard to level-1 (calibrated spectra) as well as level-2 data, consisting of retrieved altitude profiles of a variety of trace gases. These retrievals will be thoroughly characterized as well as compared to externally available datasets (e.g. from simultaneous AirCore observations).