+ Surface 2D and 3D data of monthly mean CO2 mole fractions

Files: NISMON-CO2_v2022.1_${var}_${data}.nc

-- [var] ---
co2tot: Posterior total CO2
co2fos: CO2 from fossil fuel emissions
co2bio: Posterior CO2 from terrestrial biosphere
co2ocn: Posterior CO2 from the ocean
co2bb : Posterior CO2 from biomass burnings

* Note that an arbitrary offset is needed for all the variables other than co2tot,
 when comparing with observations.

-- [data] ---
sfc2D: 2-dimensional data at the first model layer
3D   : 3-dimensional data interpolated to pressure coordinates in vertical

* Note that all the data are arrayed on 2.5 x 2.5 degree grids, which are interpolated from
 the original NICAM's icosahedral grids (~223km).