Improvement of the retrieval algorithm for GOSAT SWIR XCO<sub>2</sub> and XCH<sub>4</sub> and their validation using TCCON data
The column-averaged dry-air mole fractions of carbon dioxide and methane (XCO<sub>2</sub> and XCH<sub>4</sub>) have been retrieved from Greenhouse gases Observing SATellite (GOSAT) Short-Wavelength InfraRed (SWIR) observations and released as a SWIR L2 product from the Nation...
Main Authors: | , , , , , , , , , , , , , , , , , , , , , , , , , , , , |
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Format: | Article |
Language: | English |
Published: |
Copernicus Publications
2013-06-01
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Series: | Atmospheric Measurement Techniques |
Online Access: | http://www.atmos-meas-tech.net/6/1533/2013/amt-6-1533-2013.pdf |
Summary: | The column-averaged dry-air mole fractions of carbon dioxide and methane (XCO<sub>2</sub> and XCH<sub>4</sub>) have been retrieved from Greenhouse gases Observing SATellite (GOSAT) Short-Wavelength InfraRed (SWIR) observations and released as a SWIR L2 product from the National Institute for Environmental Studies (NIES). XCO<sub>2</sub> and XCH<sub>4</sub> retrieved using the version 01.xx retrieval algorithm showed large negative biases and standard deviations (−8.85 and 4.75 ppm for XCO<sub>2</sub> and −20.4 and 18.9 ppb for XCH<sub>4</sub>, respectively) compared with data of the Total Carbon Column Observing Network (TCCON). Multiple reasons for these error characteristics (e.g., solar irradiance database, handling of aerosol scattering) are identified and corrected in a revised version of the retrieval algorithm (version 02.xx). The improved retrieval algorithm shows much smaller biases and standard deviations (−1.48 and 2.09 ppm for XCO<sub>2</sub> and −5.9 and 12.6 ppb for XCH<sub>4</sub>, respectively) than the version 01.xx. Also, the number of post-screened measurements is increased, especially at northern mid- and high-latitudinal areas. |
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ISSN: | 1867-1381 1867-8548 |