THE GEISA SYSTEM IN 1996 - TOWARDS AN OPERATIONAL TOOL FOR THE 2ND-GENERATION VERTICAL SOUNDERS RADIANCE SIMULATION

Since their creation, in 1974, the GEISA (Gestion et Etude des Informa tions Spectroscopiques Atmospheriques: Management and Study of Atmosph eric Spectroscopic Information) database system (more than 730 000 ent ries between 0 and 22 656 cm(-1), corresponding to 40 molecules and 86 isotopic species, in its 1992 edition) and the associated software ha ve been widely used for forward atmospheric radiative transfer modelli ng, with the maximum reliability, tractability and efficiency. For the upcoming high spectral resolution sounders like IASI (Infrared Atmosp heric Sounding Interferometer) and AIRS (Atmospheric InfraRed Sounder) , more complete and accurate laboratory measurements of spectroscopic parameters, presently included in the databases, are required, and mor e sophisticated theoretical radiative transfer modelling should be dev eloped. Consequently, it is intended to elaborate the GEISA database a s an interactive tool, named GEISA/IASI, designed for providing spectr oscopic information tailored to the IASI sounding radiative transfer m odelling. (C) 1998 Elsevier Science Ltd. All rights reserved.