The Cryogenic Limb Array Etalon Spectrometer (CLAES) measured vertical profiles of temperature and concentrations of ozone, methane, water vapour, nitrogen oxides, and other important species, including CFCs, in the stratosphere. CLAES also maps the horizontal and vertical distributions of aerosols in the stratosphere. These measurements are analysed to better understand the photochemical, radiative, and dynamical processes taking place in the ozone layer.

CLAES was built by an instrument team based at Lockheed Palo Alto and launched on the Upper Atmosphere Research Satellite (UARS) on 12th September 1991. CLAES had a design lifetime of 18 months, beginning on 1st October 1991 and ceasing operations on 5th May 1993. The Principal Investigator is Dr Aidan E. Roche. CLAES makes measurements of thermal emission from the Earth's limb in a number of spectral regions which are then used to derive stratospheric altitude profiles of temperature, pressure, ozone (O3), water vapour (H2O), methane (CH4), nitrous oxide (N2O), nitrogen oxide (NO), nitrogen dioxide (NO2), dinitrogen pentoxide (N2O5), nitric acid (HNO3), chlorine nitrate (ClONO2), CFCl3, CF2Cl2. Aerosol extinction coefficients are also calculated for each spectral region. Further details of the instrument are given in the BADC help file.

The data coverage extends from 80°S to 80°N, but at any one time this is restricted to 34°S to 80°N or 34°N to 80°S. The vertical coverage of the measurements is from the tropopause to the lower mesosphere (10-60km). The range over which retrievals are valid is outlined in the help file.

The dataset contains measured global temperature, pressure, O3, H2O, CH4, N2O, NO, NO2, N2O5, HNO3, ClONO2, CFCl3, CF2Cl2 and aerosol extinction measurements. Data are level 3A product (gridded in time and latitude along the satellite track) between 80N - 80S, 10-60 Km, October 1991 - May 1993. This dataset is public.