Improved Limb Atmospheric Spectrometer (ILAS) for stratospheric ozone layer measurements by solar occultation technique

The Improved Limb Atmospheric Spectrometer (ILAS) on board the Advanced Ear th Observing Satellite (ADEOS) obtained 8 months of data for trace gas;spec ies from November 1996 to June 1997 for studies of the stratospheric ozone layer over the high-latitude regions in both the Southern and Northern Hemi spheres. The atmospheric parameters observed by ILAS were vertical profiles of ozone, nitric acid, nitrogen dioxide, nitrous oxide, methane, water vap or, aerosol extinction coefficient (at 780 nm), temperature, and pressure. Version 3.10 of the operational data processing algorithm was used to retri eve the corresponding geophysical profiles, which have been compared whenev er possible with independent correlative measurements. Selected examples of ILAS products for ozone, nitric acid, and aerosol extinction coefficient ( at 780 nm) are provided. The corresponding data is now publicly available f or further analyses by the atmospheric community.