Cryogenic Limb Array Etalon Spectrometer (CLAES) Instrument Overview

Abstract

The Cryogenic Limb Array Etalon Spectrometer (CLAES) is one of a complement of instruments on the NASA Upper Atmosphere Research Satellite which is expected to study atmospheric photochemistry, energy input, and dynamics following a 1991 launch. CLAES measures stratospheric altitude profiles of temperature, pressure, O3, H2O, CH4, N2O, NO, NO2, N2O5, HNO3, ClONO2, HCl, CFC-11, and CFC-12. These data are obtained typically between 10 and 60 km, with 2.5-km vertical resolution and 500-km horizontal grid size. Coverage is obtained between latitudes 80 deg north and south, thereby providing substantial coverage of the Antarctic spring polar ozone-hole region. CLAES derives the listed geophysical parameters from measurement of earth-limb spectral emissions between 3.5 and 13 microns. Brief discussions of the measurement concept, instrument design, and performance are presented, followed by a more detailed discussion of scientific capabilities and measurement modes.