AsA 2022 balloon-borne intercomparison campaign

PI: Dr. M. Ghysels-Dubois, Groupe de Spectrométrie Moléculaire et Atmosphérique (GSMA, UMR CNRS 7331), CNRS, France. Email:

Since 2020, we coordinate efforts at a European and international levels in order to evaluate atmospheric hygrometers in order to prepare them for TNA flights within a European research infrastructure and allow significant advancements in science. Additionally to this task, efforts have been conducted to foster the emergence of innovative sounding solutions, overcoming current limitations of well-established techniques. Indeed, upper air water vapor remains to date a technical challenge.

The AsA 2022 balloon-borne intercomparison campaign complements the AQUAVIT-4 chamber intercomparison campaign (PI: Dr. M. Ghysels-Dubois) which has occurred from March 21st to April 8, 2022 at the AIDA simulation chamber (Karlshrue Institute of Standards and Technology, Germany). During this last, atmospheric hygrometers and reference instruments were compared in simulated controlled conditions simulating upper tropospheric and  stratospheric conditions. 

            Additionally, the HYGROMATMO national project, funded by CNES, aims to calibrate the Pico-Light H2O hygrometer against humidity standards in the frame of a collaboration with LNE-Cnam and LNE-CETIAT (national metrological institutes) and to test a new kind of humidity standards generator under development at LNE-Cnam and to adapt standards test benches so they can reproduce realistic atmospheric conditions and flight dynamics.

The AsA2022 balloon-borne intercomparison campaign occurred from the CNES launch facility in Aire-sur-l’Adour (France) from September 12 to 23, 2022. In this frame,15 balloon flights were organized under small rubber balloons, able to carry instruments lighter than 3kg. 

Three of the balloons, carrying the NOAA frost-point hygrometer (USA, reference instrument here) were launched from the Aeroclub d’Aire-sur-l’Adour, 600 m away, under the responsability of the CNRS.

            In this frame, we compared dedicated balloon-borne hygrometers: Pico-Light H2O, the micro hygrometer, the NOAA FPH and meteorological sondes (M20 from MeteoModem and iMet-4).