+ Hourly CO2 mole fraction data at ground-based stations

Files: NISMON-CO2_v2022.1_allcomp_${site}.nc 

site: site code (see observation_list.ver.2022.1.csv)

Each file contains 5 components of CO2 mole fractions:
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.