Review status: this preprint is currently under review for the journal AMT.
A lightweight balloon-borne mid-infrared hygrometer to probe the middle atmosphere: Pico-Light H2O. Comparison with Aura-MLS v4 and v5 satellite measurements
Mélanie Ghysels1,Georges Durry1,Nadir Amarouche2,Jean-Christophe Samake2,Fabien Frérot2,and Emmanuel D. Rivière1Mélanie Ghysels et al.Mélanie Ghysels1,Georges Durry1,Nadir Amarouche2,Jean-Christophe Samake2,Fabien Frérot2,and Emmanuel D. Rivière1
1Groupe de Spectrométrie Moléculaire et Atmosphérique (GSMA, UMR CNRS 7331), Université de Reims, UFR Sciences Exactes et Naturelles, Moulin de la Housse B.P. 1039, 51687 Reims CEDEX 2, France
2INSU Division Technique, 1 place Aristide Briand, 92195 Meudon CEDEX France
1Groupe de Spectrométrie Moléculaire et Atmosphérique (GSMA, UMR CNRS 7331), Université de Reims, UFR Sciences Exactes et Naturelles, Moulin de la Housse B.P. 1039, 51687 Reims CEDEX 2, France
2INSU Division Technique, 1 place Aristide Briand, 92195 Meudon CEDEX France
Received: 02 Jul 2020 – Accepted for review: 31 Aug 2020 – Discussion started: 14 Oct 2020
Abstract. Newly developed mid-infrared lightweight hygrometer, Pico-Light H2O has been tested in-flight on February 19, 2019 and October 16, 2019. It has been flown under a 1200 g rubber balloon operated by CNES from the Aire-sur-l'Adour facility (France) within the E.U. funded HEMERA WP11. During these two flights, we were able to obtain coincident MLS v4 and v5 water vapor and temperature profiles, leading to an inter-comparison between Pico-Light and Aura-MLS water vapor and temperature retrievals. Results from the comparison are in line with previous reported studies . Here, differences in the mid-latitude stratosphere and upper troposphere (20–316 hPa) are within 7 % and 64 % respectively. Largest differences with MLS v4 occurring within the upper troposphere nearby the cold point tropopause. The v5 MLS data have been corrected for observed dry bias nearby the tropopause, allowing to partially solve the observed discrepancies. Additionally, on February 19, the hygrometer has flown within an air filament from polar latitudes most of the flight for which a signature is observed on the water vapor profile and confirmed with ozone reanalysis from ERA 5and potential vorticity from MIMOSA advection model.
Understanding the processes which regulate the entry of water into the lower stratosphere is essential to address the impact of water vapor on the climate, but also for the future balance of the ozone layer. Developing lightweight hygrometers is of importance to allow frequent sounding in support of such understanding. In this frame, a new lightweight hygrometer, named Pico-Light H2O, has been tested twice in-flight under rubber balloon in 2019.
Understanding the processes which regulate the entry of water into the lower stratosphere is...