A plan for ILAS-II correlative measurements with emphasis on a validation balloon campaign at Kiruna-esrange

The present paper describes a plan for correlative measurements dedicated to the satellite sensor ILAS (Improved Limb Atmospheric Spectrometer)-II. ILAS-II, a solar occultation sensor with three infrared spectrometers and a visible spectrometer, is a successor to ILAS, and is scheduled to be launched in February 2002. ILAS-II will measure vertical profiles of ozone (O-3), nitric acid (HNO3), nitrogen dioxide (NO2), nitrous oxide (N2O), methane (CH4), water vapor (H2O), chlorine nitrate (ClONO2) mixing ratios, aerosol extinction coefficients, and atmospheric temperature and pressure in the altitude range of similar to 10-60 kin (depending on species), with an altitude resolution of 1 km in high latitudes. As done for ILAS, correlative measurements for ILAS-II are planned. The present plan for ILAS-II is similar to that for ILAS. The balloon campaign at Kiruna-Esrange (68N, 21E) for ILAS-II will be considered as the core one among various other correlative experiments. The anticipated period of the first balloon campaign for ILAS-II is around August-September 2002 when ILAS-II will be in operation and will measure stratospheric profiles over Kiruna. Another candidate period may be around November-December 2001. Other plans for correlative measurements will be briefly presented. Some of the ILAS-II correlative measurement data might be useful for validation of other satellite sensors, and vice versa.