Analysis of SAGE III Spectral Survey Solar Occultation Events
Abstract
The Stratospheric Aerosol and Gas Experiment III (SAGE III) detector includes an 800-element CCD linear array that provides continuous spectral coverage between 290 and 1030 nm. During routine solar occultation measurements, SAGE III uses only 87 discrete spectral bands to retrieve gaseous species and aerosol parameters. SAGE III also has the capability to operate in a full spectral survey mode, sampling the entire spectral range of the detector, albeit at a decreased sampling rate. The spectral survey mode is primarily used to calibrate the instrument wavelength registration during exoatmospheric scans. On a few occasions, a full spectral survey of the atmosphere has been conducted. This spectral information serves as a useful SAGE III diagnostic tool: Does SAGE III use the optimal set of pixels for its gaseous species retrieval? Is the O4 absorption signature a suitable method to improve altitude registration in the lower stratosphere and upper troposphere? Can SAGE III detect BrO? Is the etaloning behavior of the CCD at infrared wavelengths stable throughout an occultation event and is this information useful for the solar mode retrievals? Comparisons of coincident measurements taken by the Gas and Aerosol Monitoring Sensor (GAMS) during the SAGE III Ozone Loss Validation Experiment (SOLVE II) field campaign will also be presented. GAMS measures the same wavelength region as SAGE III but at a higher spectral resolution and a faster sampling rate. Two SAGE III spectral survey events were made coincident with GAMS measurements on SOLVE II DC-8 science flights, providing an opportunity for a comparison of spectral features and slant path transmittance through the same air mass.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2003
- Bibcode:
- 2003AGUFM.A42C0783W
- Keywords:
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- 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 0340 Middle atmosphere: composition and chemistry;
- 0360 Transmission and scattering of radiation