Estimates of Arctic-boreal wetland methane emissions from bottom-up and top-down approaches using the JSBACH v3.2 model and the Jena CarboScope Global Atmospheric Inversion System

This dataset accompanies the study "A top-down evaluation of bottom-up estimates to reduce uncertainty in methane emissions from Arctic wetlands" published at Biogeosciences (Basso et al., 2026). It consists of a single NetCDF file containing a set of bottom-up wetland methane estimates from the JSBACH v3.2 model (a component of the MPI Earth System Model), which were used as prior fluxes in the atmospheric inversion system. The file also contains posterior (optimised) methane wetland fluxes (CH₄), which were estimated by atmospheric inverse modelling using the Jena CarboScope Global Atmospheric Inversion System. These estimates are the result of a series of inversion experiments, each of which incorporates JSBACH-generated wetland CH₄ fluxes based on different CH₄ production Q₁₀ values (1.4, 1.8 and 2.2), representing the temperature dependence of CH₄ production, and different baseline fCH₄ fraction values (0.33, 0.35 and 0.38), defining the fraction of anaerobically mineralised carbon converted to CH₄. All other JSBACH and inversion settings were kept constant. These surface fluxes are monthly emission from wetlands, with a horizontal resolution of ~3.8° latitude by 5° longitude. The fluxes cover the period from January 2010 to December 2021 and units are TgCH4/month.