Japan Geoscience Union Meeting 2023

Presentation information

[E] Oral

A (Atmospheric and Hydrospheric Sciences ) » A-CG Complex & General

[A-CG37] Satellite Earth Environment Observation

Fri. May 26, 2023 9:00 AM - 10:30 AM 104 (International Conference Hall, Makuhari Messe)

convener:Riko Oki(Japan Aerospace Exploration Agency), Yoshiaki HONDA(Center for Environmental Remote Sensing, Chiba University), Yukari Takayabu(Atmosphere and Ocean Research Institute, the University of Tokyo), Tsuneo Matsunaga(Center for Global Environmental Research and Satellite Observation Center, National Institute for Environmental Studies), Chairperson:Tsuneo Matsunaga(Center for Global Environmental Research and Satellite Observation Center, National Institute for Environmental Studies)

9:15 AM - 9:30 AM

[ACG37-02] Global CO2 and CH4 flux extimates based on satellite observations by GOSAT and GOSAT-2

*Makoto Saito1, Yosuke Niwa1, Hiroshi Takagi1, Akihide Kamei1, Tazu Saeki1, Tomohiro Shiraishi1, Hibiki M Noda1, Ryuichi Hirata1, Kazutaka Murakami1, Isamu Morino1, Hisashi Yashiro1, Yukio Yoshida1, Shamil Maksyutov1, Tsuneo Matsunaga1 (1.National Institute for Environmental Studies)

Keywords:satellite observations, greenhouse gases, atmospheric inversion

Understanding changes in the Earth system and the impact of human activity is significant scientific challenge. Earth explorer satellite missions provide essential observational data to study the scientific issues in local, regional, and global scales. Greenhouse gases Observing SATellite (GOSAT) and the successor GOSAT-2 are Japanese Earth explore satellite missions for monitoring global distribution of greenhouse gases. This study describes overviews of global surface carbon dioxide (CO2) and methane (CH4) flux estimates based on respective TANSO-FTS and TANSO-FTS-2 Column-averaged Dry-air Mole Fraction Products (GOSAT and GOSAT-2 SWIR Level 2 Products) being retrieved from the spectral data acquired by GOSAT and GOSAT-2 satellites. The flux estimates derived from GOSAT SWIR Level 2 Products have been released as GOSAT Level 4 Products, whose latest versions cover variability of global CO2 and CH4 fluxes for 2009 and 2020. We show that the GOSAT Level 4 Products using a fixed-lag Kalman smoother built on an atmospheric tracer transport model NIES-TM can provide an information to infer carbon cycle over regional scale. As a case study of surface flux estimate over the blank region of surface observational stations, an insight regarding relationship between CH4 emissions and reginal meteorological conditions in central South America is given in this study by using the satellite observations effectively. New global surface flux estimates derived from GOSAT-2 SWIR Level 2 Products are developed using a global circulation mode NICAM-based Inverse Simulation for Monitoring CO2 and CH4 (NISMON) system. In the estimate uncertainties being inherent in the GOSAT-2 SWIR Level 2 Products results in erroneous distributions of flux estimates, especially over the African continent. We demonstrate latest results of GOSAT-2 Level 4 product using updated GOSAT-2 SWIR Level 2 Products and their comparison with other observational and model estimate results.