[A-CG36] Satellite Earth Environment Observation

[ACG36-04] Spatial and Temporal Variations of XCO₂ and XCH₄ observed by GOSAT and GOSAT-2 in 2019 - 2020

★Invited Papers

*Tsuneo Matsunaga¹, Isamu Morino¹, Hirofumi Ohyama¹, Jiye Zeng¹, Hibiki M Noda¹, Makoto Saito¹, Yukio Yoshida¹, Akihide Kamei¹, Fumie Kawazoe¹, Tazu Saeki¹ (1.Center for Global Environmental Research and Satellite Observation Center, National Institute for Environmental Studies)

Keywords:Greenhouse gas, Carbon Dioxide, Methane

Fourier transform spectrometers (FTS) onboard GOSAT (launched in 2009) and GOSAT-2 (launched in 2018) have been observing the Earth's atmosphere in the short wavelength infrared region for about 12 and 2 years respectively. The column-averaged dry-air mole fractions of CO₂ (XCO₂) and CH₄ (XCH₄) were calculated from these FTS data and distributed to general public from GOSAT Data Archive Service (https://data2.gosat.nies.go.jp/index_en.html) and GOSAT-2 Product Archive (https://prdct.gosat-2.nies.go.jp/en/index.html) as GOSAT and GOSAT-2 Level 2 standard products. Their latest versions are V02.90/V02.91 and V02.95/V02.96 (bias corrected) for GOSAT and V01.03 (proxy) and V01.04 (full physics) for GOSAT-2, respectively.

It is already found that the current GOSAT-2 full physics XCO₂ and XCH₄ products have significant biases which are spatially and temporally variable. To investigate such characteristics of GOSAT-2 data, following comparisons are being conducted.

(1) Comparison between GOSAT-2 Level 2 products and ground-based data

(2) Comparison between GOSAT and GOSAT-2 Level 2 products

(3) Comparison of whole-atmosphere monthly mean CO₂ and CH₄ concentrations derived from GOSAT and GOSAT-2 L2 products independently.



Comparison results and suggestions for future product improvements will be discussed in the presentation.