Improvement of the retrieval algorithm for GOSAT SWIR XCO2 and XCH4 and their validation using TCCON data

Authors

Y Yoshida, National Insitute for Environmental Studies, Japan
N Kikuchi, National Institute for Environmental Studies,Japan
I Morino, National Institute for Environmental Studies, Japan
O Uchino, National Institute for Environmental Studies,Japan
S Oshchepkov, National Institute for Environmental Studies,Japan
A Bril, National Institute for Environmental Studies,Japan
T Saeki, National Institute for Environmental Studies,Japan
N Schutgens, University of Tokyo
G C. Toon, California Institute of Technology
D Wunch, California Institute of Technology
C M. Roehl, California Institute of Technology
P O. Wennberg, California Institute of Technology
D W. T Griffith, University of WollongongFollow
N M. Deutscher, University of WollongongFollow
T Warneke, University of Bremen
J Notholt, University of Bremen
J Robinson, National Institute of Water and Atmospheric Research, New Zealand
V Sherlock, National Institute of Water and Atmospheric Research, New Zealand
B Connor, National Institute of Water and Atmospheric Research, New Zealand
M Rettinger, Karlsruhe Institute of Technology
R Sussmann, IMK-IFU, Germany
P Ahonen, Finnish Meteorological Institute
P Heikkinen, FMI-Arctic Research Center,Finnish Meteorological Institute
E Kyro, Finnish Meteorological Institute
J Mendonca, University of Toronto
K Strong, University of Toronto
F Hase, Karlsruhe Institute of Technology
S Dohe, Karlsruhe Institute of Technology
T Yokota, National Institute for Environmental Studies,Japan

RIS ID

81795

Publication Details

Yoshida, Y., Kikuchi, N., Morino, I., Uchino, O., Oshchepkov, S., Bril, A., Saeki, T., Schutgens, N., Toon, G. C., Wunch, D., Roehl, C. M., Wennberg, P. O., Griffith, D. W. T., Deutscher, N. M., Warneke, T., Notholt, J., Robinson, J., Sherlock, V., Connor, B., Rettinger, M., Sussmann, R., Ahonen, P., Heikkinen, P., Kyro, E., Mendonca, J., Strong, K., Hase, F., Dohe, S. & Yokota, T. (2013). Improvement of the retrieval algorithm for GOSAT SWIR XCO2 and XCH4 and their validation using TCCON data. Atmospheric Measurement Techniques, 6 (6), 1533-1547.

Abstract

The column-averaged dry-air mole fractions of carbon dioxide and methane (XCO2 and XCH4) 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). XCO2 and XCH4 retrieved using the version 01.xx retrieval algorithm showed large negative biases and standard deviations (−8.85 and 4.75 ppm for XCO2 and −20.4 and 18.9 ppb for XCH4, 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 XCO2 and −5.9 and 12.6 ppb for XCH4, respectively) than the version 01.xx. Also, the number of post-screened measurements is increased, especially at northern mid- and high-latitudinal areas.