Atmospheric Measurement Techniques (Jun 2011)

Preliminary validation of column-averaged volume mixing ratios of carbon dioxide and methane retrieved from GOSAT short-wavelength infrared spectra

  • I. Morino,
  • O. Uchino,
  • M. Inoue,
  • Y. Yoshida,
  • T. Yokota,
  • P. O. Wennberg,
  • G. C. Toon,
  • D. Wunch,
  • C. M. Roehl,
  • J. Notholt,
  • T. Warneke,
  • J. Messerschmidt,
  • D. W. T. Griffith,
  • N. M. Deutscher,
  • V. Sherlock,
  • B. Connor,
  • J. Robinson,
  • R. Sussmann,
  • M. Rettinger

DOI
https://doi.org/10.5194/amt-4-1061-2011
Journal volume & issue
Vol. 4, no. 6
pp. 1061 – 1076

Abstract

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Column-averaged volume mixing ratios of carbon dioxide and methane retrieved from the Greenhouse gases Observing SATellite (GOSAT) Short-Wavelength InfraRed observation (GOSAT SWIR <i>X</i><sub>CO<sub>2</sub></sub> and <i>X</i><sub>CH<sub>4</sub></sub>) were compared with the reference calibrated data obtained by ground-based high-resolution Fourier Transform Spectrometers (g-b FTSs) participating in the Total Carbon Column Observing Network (TCCON). <br><br> Preliminary results are as follows: the GOSAT SWIR <i>X</i><sub>CO<sub>2</sub></sub> and <i>X</i><sub>CH<sub>4</sub></sub> (Version 01.xx) are biased low by 8.85 &plusmn; 4.75 ppm (2.3 &plusmn; 1.2 %) and 20.4 &plusmn; 18.9 ppb (1.2 &plusmn; 1.1 %), respectively. The standard deviation of the GOSAT SWIR <i>X</i><sub>CO<sub>2</sub></sub> and <i>X</i><sub>CH<sub>4</sub></sub> is about 1 % (1 σ) after correcting the negative biases of <i>X</i><sub>CO<sub>2</sub></sub> and <i>X</i><sub>CH<sub>4</sub></sub> by 8.85 ppm and 20.4 ppb, respectively. The latitudinal distributions of zonal means of the GOSAT SWIR <i>X</i><sub>CO<sub>2</sub></sub> and <i>X</i><sub>CH<sub>4</sub></sub> show similar features to those of the g-b FTS data except for the negative biases in the GOSAT data.