The OCO “full-physics” CO2 retrieval algorithm: expected performance based on full-orbit simulations
Abstract
We present results on the expected performance of the “full-physics” carbon dioxide concentration retrieval algorithm, originally designed to process Orbiting Carbon Observatory (OCO) data. This algorithm has been modified to work on the Greenhouse gases Observing SATellite (GOSAT) data as well. The algorithm is a standard ‘optimal-estimation’ style inversion. For each sounding, the observed spectra of reflected sunlight, as well as instrument noise characteristics and a priori estimates of meteorological and other parameters, are used to find a best-fit solution for the vertical profile of carbon dioxide concentration. The expected performance of the algorithm in the presence of instrument noise, radiative transfer errors and errors in the assumptions regarding aerosol and surface characteristics are analyzed based on a series of realistic, full-orbit simulations. Errors from approximately a dozen synthetic orbits are analyzed on a per-retrieval basis, and are also aggregated onto regional scales. A post-processing filter can reduce regional-scale biases. Expected magnitudes of per-sounding errors and regional biases in the column-average concentration of carbon dioxide (XCO2) are reported for both the OCO and GOSAT TANSO-FTS instruments.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2009
- Bibcode:
- 2009AGUFM.A43D..05O
- Keywords:
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- 0360 ATMOSPHERIC COMPOSITION AND STRUCTURE / Radiation: transmission and scattering;
- 0365 ATMOSPHERIC COMPOSITION AND STRUCTURE / Troposphere: composition and chemistry