- Concentration units: [ppm]

- NetCDF variables:

Name Units Meaning `co2mix`[ppm] CO2 concentration

(difference from initial value)`gph`[m] Geopotential height at layer base `lon`[degr] Longitudes of grid cell centers `lat`[degr] Latitudes of grid cell centers `height`[hPa] Standard pressure of layer centers `time`[seconds] Time (instantaneous) `dxyp`[m2] Grid cell area (for unit conversion) `ps`[hPa] Surface pressure `a`[hPa] Coeff. a of vertical coordinate `b`[1] Coeff. b of vertical coordinate - The 3D fields give the difference of the mixing ratio
w.r.t. the initial mixing ratio.
Therefore, the value of the
**initial mixing ratio, as given in the attribute**`ini`, has to be added. - For vertical interpolation of the fields to other coordinates,
geopotential height fields
`gph`have been provided. - (From version v3.6:)
Alternatively to
`gph`, the**air pressure at the base of each layer**can be calculated from the surface pressure`ps`and the coefficients`a`and`b`by`p = a + b*ps`.

- The 3D fields give the difference of the mixing ratio
w.r.t. the initial mixing ratio.
Therefore, the value of the