3D monthly simulations of atmospheric CH4, δ13C, and δD by using JAMSTEC's MIROC4-ACTM for 1990-2020

The dataset presents 3D-monthly simulations of atmospheric methane (CH₄) and its stable isotopic ratios (δ¹³C-CH₄ and δD-CH₄) generated using JAMSTEC’s MIROC4-based atmospheric chemistry-transport model (MIROC4-ACTM; Patra et al., SOLA, 2018). The simulations incorporate emission distributions from two key inventories—EDGARv6 and GAINSv4—to evaluate sector-specific contributions to atmospheric methane. By comparing model outputs with observations from Tohoku University, the National Institute of Polar Research (NIPR), and the Institute of Arctic and Alpine Research (INSTAAR), the simulations enable detailed tracing of emission “footprints” across different source sectors.

The bottom-up emissions used in the simulations are publicly archived at

 https://doi.org/10.5281/zenodo.11143943 (E3_gOngWunc_Scoal_gl19.nc case)

Full details of the study are available in

Chandra, N., Patra, P.K., Fujita, R. et al. Methane emissions decreased in fossil fuel exploitation and sustainably increased in microbial source sectors during 1990–2020. Commun Earth Environ 5, 147 (2024). https://doi.org/10.1038/s43247-024-01286-x