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

oleh: 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

Format: Article
Diterbitkan: Copernicus Publications 2011-06-01

Deskripsi

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 ± 4.75 ppm (2.3 ± 1.2 %) and 20.4 ± 18.9 ppb (1.2 ± 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.