25 Years of Atmospheric Science with the Balloon-borne Limb Sounder MIPAS-B

MIPAS-B (Michelson Interferometer for Passive Atmospheric Sounding - Balloon) is a balloon-borne limb-emission sounder for atmospheric research. The heart of the instrument is a Fourier spectrometer that covers the mid-infrared spectral range (4 to 14 µm) operating at a temperature of approximately 215 K. Essential for this application is the sophisticated line of sight stabilization system, which is based on an inertial navigation system and supplemented with a star camera reference system. The major scientific benefit of the instrument is the simultaneous detection of complete trace gas families in the stratosphere, without restrictions concerning time of the day and viewing directions. MIPAS-B is an in-house development that was started in the mid-eighties. It initially served as proof of concept for the proposed space borne MIPAS instrument that was later realized and operated on the ESA satellite ENVISAT between 2002 and 2012. But actually it soon became obvious that operation from stratospheric balloons offered a number of benefits to address dedicated scientific questions in an optimal way. MIPAS-B was operated in two versions during 24 flights at tropical, mid-latitudinal and arctic latitudes between 1989 and 2014 covering the `golden era' of ozone loss research and the full operational period of ENVISAT. This paper describes briefly specifications, design considerations, technological upgrades and the characterization of the instrument. Evolving skills with respect to its remote operation from ground and to data analysis in the course of the 25 years are outlined. Scientific applications in the field of atmospheric research, spectroscopy and satellite validation are highlighted with a focus on recent research concerning bromine nitrate and age of air.