Towards IASI-New Generation (IASI-NG): impact of improved spectral resolution and radiometric noise on the retrieval of thermodynamic, chemistry and climate variables

Cyril Crevoisier (1) , Cathy Clerbaux (2) , Vincent Guidard (3) , Thierry Phulpin (4) , Raymond Armante (1) , Blandine Barret (5) , Claude Camy-Peyret (6) , Jean-Pierre Chaboureau (5) , Pierre-François Coheur (7) , Laurent Crépeau (1) , Gaëlle Dufour (8) , Laurent Labonnote (9) , L. Lavanant (10) , Juliette Hadji-Lazaro (2) , Hervé Herbin (9) , Nicole Jacquinet-Husson (1) , Sébastien Payan (2) , Eric Péquignot (4) , Clémence Pierangelo (4) , Pasquale Sellitto (1, 8) , Claudia Stubenrauch (1)

1 LMD - Laboratoire de Météorologie Dynamique (UMR 8539)
2 TROPO - LATMOS
3 CNRM - Centre national de recherches météorologiques
4 CNES - Centre National d'Études Spatiales [Toulouse]
5 LAERO - Laboratoire d'aérologie
6 IPSL - Institut Pierre-Simon-Laplace
7 Spectroscopie de l'atmosphère, Service de Chimie Quantique et Photophysique
8 LISA (UMR_7583) - Laboratoire Interuniversitaire des Systèmes Atmosphériques
9 LOA - Laboratoire d’Optique Atmosphérique - UMR 8518
10 Centre de Météorologie Spatiale

Besides their strong contribution to weather forecast improvement through data assimilation, thermal infrared sounders onboard polar-orbiting platforms are now playing a key role for monitoring atmospheric composition changes. The Infrared Atmospheric Sounding Interferometer (IASI) instrument developed by the French space agency (CNES) and launched by Eumetsat onboard the Metop satellite series is providing essential inputs for weather forecasting and pollution/climate monitoring owing to its smart combination of large horizontal swath, good spectral resolution and high radiometric performance. EUMETSAT is currently preparing the next polar-orbiting program (EPS-SG) with the Metop-SG satellite series that should be launched around 2020. In this framework, CNES is studying the concept of a new instrument, the IASI-New Generation (IASI-NG), characterized by an improvement of both spectral and radiometric characteristics as compared to IASI, with three objectives: (i) continuity of the IASI/Metop series; (ii) improvement of vertical resolution; (iii) improvement of the accuracy and detection threshold for atmospheric and surface components. In this paper, we show that an improvement of spectral resolution and radiometric noise fulfill these objectives by leading to (i) a better vertical coverage in the lower part of the troposphere, thanks to the increase in spectral resolution; (ii) an increase in the accuracy of the retrieval of several thermodynamic, climate and chemistry variables, thanks to the improved signal-to-noise ratio as well as less interferences between the signatures of the absorbing species in the measured radiances. The detection limit of several atmospheric species is also improved. We conclude that IASI-NG has the potential for strongly benefiting the numerical weather prediction, chemistry and climate communities now connected through the European GMES/Copernicus initiative.

Domaines: Physique Atmosphérique et Océanique [physics.ao-ph]; Sciences de l'environnement

Cyril Crevoisier, Cathy Clerbaux, Vincent Guidard, Thierry Phulpin, Raymond Armante, et al.. Towards IASI-New Generation (IASI-NG): impact of improved spectral resolution and radiometric noise on the retrieval of thermodynamic, chemistry and climate variables. Atmospheric Measurement Techniques, 2014, 7, pp.4367-4385. ⟨10.5194/amt-7-4367-2014⟩. ⟨hal-00921248⟩