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Instrument: CLAES : Cryogenic Limb Array Etalon Spectrometer
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Associated Platforms

Spectral/Frequency Information
Wavelength Keyword: Infrared > Reflected
Spectral/Frequency Coverage/Range: 3.5 μm to 12.9 μm

Related Data Sets
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The Space Shuttle Discovery carrying UARS was launched on September 12, 1991 from Kennedy Space Flight Center. UARS was released to orbit on September 15, 1991, and the Cryogenic Limb Array Etalon Spectrometer (CLAES) began scientific observations of the earth's upper atmosphere October 1, 1991.

The CLAES experiment measures temperature profiles, and concentrations of ozone, methane, water vapor, 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 analyzed to better understand the photochemical, radiative, and dynamical processes taking place in the ozone layer.

CLAES measures ozone (O3) and the following stratospheric gases: 1) Source Species * Nitrous oxide (N2O)-produced in soils and oceans * Fluorocarbon-11 (CFCl3)-refrigerants, foaming agents * Fluorocarbon-12 (CF2Cl2)-refrigerants, foaming agents * Methane (CH4)-biogenic processes * Water vapor (H2O) 2) Ozone-Destructive Species * Nitric oxide (NO) * Nitrogen dioxide (NO2) 3) Reservoir and Sink Species * Nitric acid (HNO3) * Chlorine nitrate (ClONO2) * Dinitrogen pentoxide (N2O5) * Hydrogen cloride (HCl) Carbon Dioxide (CO2) emissions are measured and used to deduce temperature and pressure. Aerosol absorption coefficients are also derived.

CLAES Science Objectives ------------------------

CLAES produced a 19-month global database showing the vertical distributions of important ozone-layer gases in the stratosphere and their variation with time of day, season, latitude, and longitude. With the other UARS instruments, these data are contributing to a better understanding of the processes that control ozone depletion in the middle and northern latitudes, including volcanic effects, as well as the seasonal development and breakup of the Antarctic ozone hole.

Online Resources

Instrument Logistics
Data Rate: 1300 measurement sets per day
Instrument Start Date: 1991-10-01
Instrument Stop Date: 1993-05-05
Instrument Owner: NASA