GEISA : spectroscopic database

spectroscopic database
Project website

The context

Adequate tools are required to perform reliable radiative transfer modelling calculations to meet the needs of communities involved in understanding the atmospheres of the Earth and other planets. Among these tools compilations of spectroscopic parameters are used for a vast array of applications and especially for planetary atmospheric remote sensing. Consequently, there is an acute need for comprehensive, trustworthy and operational interactive spectroscopic databases to benefit the research in direct and inverse radiative transfer. In this context, since over three decades, the ARA (Atmospheric Radiation Analysis) group at LMD (Laboratoire de Météorologie Dynamique, France) has developed GEISA (Gestion et Etude des Informations Spectroscopiques Atmosphériques: Management and Study of Atmospheric Spectroscopic Information), a computer accessible database system [Chédin et al. (1982), Husson et al. (1992), Jacquinet-Husson et al. (19992005200820112016), Armante et al (2016), Delahaye et al 2020, designed to facilitate accurate and fast forward, calculations of atmospheric radiative transfer using a line-by-line and (atmospheric) layer-by-layer approach. This effort has proven to be beneficial to the atmospheric scientific community participating in direct and inverse radiative transfer studies.

The role of molecular spectroscopy in modern atmospheric research has entered a new phase with the advent of highly sophisticated spectroscopic instruments and computers. For example, the performance of Earth atmospheric sounders like AIRS, in the USA, and IASI in Europe, which have a better vertical resolution and accuracy, compared to the previous existing satellite infrared vertical sounders, is directly related to the quality of the spectroscopic parameters of the optically active gases, since these are essential input in the forward models used to simulate recorded radiance spectra. Consequently, a strong demand exists for highly comprehensive, well validated, efficiently operational, and desirably interactive computer-based spectroscopic databases to benefit the research in direct and inverse radiative transfer.

In this purpose, GEISA is currently involved in activities related to the assessment of the capabilities IASI. Since the METOP European polar satellite launch (October 19th 2006, october 2012), GEISA is the reference spectroscopic database for the validation of the level-1 IASI data (CAL/VAL activities), using the 4A (Automatized Atmospheric Absorption Atlas) radiative transfer model [Scott (1974), Scott and Chédin (1981); 4A/LMD; 4A/OP co-developed by LMD and Noveltis with the support of CNES].

GEISA is maintained :

by the Ara group at LMD (Ecole Polytechnique) for its scientific part.

by the AERIS/ ESPRI Data Centre (former Ether) group (CNRS Centre National de la Recherche Scientifique-France) at IPSL (Institut Pierre Simon Laplace) for its technical part.

Products available

3 versions of the database are available : 2011, 2015 and 2020 version for line transition parameters, absorption cross-sections and Microphysical and optical properties of atmospheric aerosols.

Data access are open and free.

Contacts

Point of contact

Cathy Boonne (CDS ESPRI, Institut Pierre Simon Laplace) cathy.boonne@ipsl.jussieu.fr

Raymond Armante (Laboratoire de Météorologie Dynamique) Coordinator GEISA-AERIS raymond.armante@lmd.polytechnique.fr

Thibault Delahaye (Laboratoire de Météorologie Dynamique) Coordinator spectroscopy and kinetic data CDS ESPRI thibault.delahaye@lmd.ipsl.fr

tag Tags

Thematiques :aerosoldataset
Typologie de projet :Data banks and laboratory data
Offres de services :catalogue

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