File Formats

File format (3D concentrations)

3D concentration fields are provided as NetCDF files (separate files for each year).

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

Remarks:

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.