Presentation Information
[AAS08-P36]Long-term Greenhouse Gas Observations by GOSAT Series Satellites and NIES Products
*Tazu Saeki1, Tsuneo Matsunaga1, Isamu Morino1, Yukio Yoshida1, Makoto Saito1, Hibiki M Noda1, Hirofumi Ohyama1, Yu Someya1, Yosuke Niwa1, Hisashi Yashiro1, Hiroshi Tanimoto1, Takafumi Sugita1, Tamaki Fujinawa1, Akihide Kamei1, Fumie Kawazoe1, Yukinori Yokoshima1, Yoshihiro Itahashi1 (1.National Institute for Environmental Studies)
Keywords:
Greenhouse gases,Satellite remote sensing,GOSAT,Data products
The Greenhouse Gases Observing SATellite (GOSAT), its successor, GOSAT-2, collectively known as the GOSAT series, have observed carbon dioxide (CO2) and methane (CH4) since 2009 and 2018, respectively, providing one of the longest and most consistent global greenhouse gas (GHG) observation records from space. Jointly developed by the National Institute for Environmental Studies (NIES), the Ministry of the Environment, Japan, and the Japan Aerospace Exploration Agency (JAXA), the GOSAT series aims to advance scientific understanding of global CO2 and CH4 cycles and to support climate research and related policymaking.
NIES is responsible for higher-level data processing, validation and distribution of GOSAT series data products. Observational data are routinely processed at the NIES data processing systems and distributed through GOSAT series data platforms. The product suite spans multiple processing levels: calibrated radiance spectra (Level 1); retrieved results of the global column-averaged dry-air mole fractions of CO2 and CH4 from GOSAT and GOSAT-2 (XCO2 and XCH4) , and carbon monoxide for GOSAT-2 (XCO) (Level 2); gridded and temporally averaged concentrations (Level 3 for GOSAT); and CO2 and CH4 surface flux estimates derived through inverse modeling (Level 4A), along with simulated concentrations (Level 4B). The Level 2 XCO2, XCH4 and XCO products are validated using observations from the Total Carbon Column Observing Network (TCCON), a global ground-based network of solar-viewing Fourier transform spectrometers. These products have contributed essential datasets to major climate assessments, including the IPCC Sixth Assessment Report, and were submitted to the first Global Stocktake in 2022 under the Paris Agreement.
The third satellite in the series, the Global Observing SATellite for Greenhouse gases and Water cycle (GOSAT-GW), launched in June 2025, carries the TANSO-3 grating spectrometer with wide and focus observation modes for monitoring XCO2, XCH4, and nitrogen dioxide from local to global scales. Product processing for these gases is ongoing at NIES, and the resulting datasets are expected to support global GHG monitoring and verification of national anthropogenic emission inventories.
NIES is responsible for higher-level data processing, validation and distribution of GOSAT series data products. Observational data are routinely processed at the NIES data processing systems and distributed through GOSAT series data platforms. The product suite spans multiple processing levels: calibrated radiance spectra (Level 1); retrieved results of the global column-averaged dry-air mole fractions of CO2 and CH4 from GOSAT and GOSAT-2 (XCO2 and XCH4) , and carbon monoxide for GOSAT-2 (XCO) (Level 2); gridded and temporally averaged concentrations (Level 3 for GOSAT); and CO2 and CH4 surface flux estimates derived through inverse modeling (Level 4A), along with simulated concentrations (Level 4B). The Level 2 XCO2, XCH4 and XCO products are validated using observations from the Total Carbon Column Observing Network (TCCON), a global ground-based network of solar-viewing Fourier transform spectrometers. These products have contributed essential datasets to major climate assessments, including the IPCC Sixth Assessment Report, and were submitted to the first Global Stocktake in 2022 under the Paris Agreement.
The third satellite in the series, the Global Observing SATellite for Greenhouse gases and Water cycle (GOSAT-GW), launched in June 2025, carries the TANSO-3 grating spectrometer with wide and focus observation modes for monitoring XCO2, XCH4, and nitrogen dioxide from local to global scales. Product processing for these gases is ongoing at NIES, and the resulting datasets are expected to support global GHG monitoring and verification of national anthropogenic emission inventories.