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

The Improved Limb Atmospheric Spectrometer (ILAS) on board the Advanced Earth Observing Satellite (ADEOS) obtained 8 months of data for trace gas species from November 1996 to June 1997 for studies of the stratospheric ozone layer over the high-latitude regions in both the Southern and Northern Hemispheres. The atmospheric parameters observed by ILAS were vertical profiles of ozone, nitric acid, nitrogen dioxide, nitrous oxide, methane, water vapor, aerosol extinction coefficient (at 780 nm), temperature, and pressure. Version 3.10 of the operational data processing algorithm was used to retrieve the corresponding geophysical profiles, which have been compared whenever 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 for further analyses by the atmospheric community.