Data format¶

Joseki produces atmospheric profile datasets in the NetCDF format using the xarray library which provides a comprehensive, robust and convenient interface to read, write, manipulate and visualize NetCDF data.

Metadata conventions¶

The NetCDF format allows storing metadata alongside data. Joseki’s dataset metadata follows the conventions for Climate and Forecast (v1.10).

Standard names¶

The Climate and Forecast (CF) conventions define standard names to describe variables. Joseki’s datasets comply with CF Standard Name Table Version 81, 25 April 2023 except for the following variables for which a standard name did not exist (hence we derived one):

Standard name	Long name	Units
`air_number_density`	`air number density`	`m^-3`

Structure¶

A dataset includes 4+ data variables:

Standard name	Long name	Symbol	Units
`air_pressure`	`air pressure`	`p`	`Pa`
`air_temperature`	`air temperature`	`t`	`K`
`air_number_density`	`air number density`	`n`	`m^-3`
`mole_fraction_of_M_in_air`	`mole fraction of M in air`	`x_M`	`dimensionless`

where M is the chemical formula of the given molecule (e.g. mole_fraction_of_H2O_in_air is associated with the symbol x_H2O), and one of the two following coordinate variables:

Standard name	Long name	Symbol	Units
`altitude`	`altitude`	`z`	`km`
`layer_center_altitude`	`layer center altitude`	`z`	`km`

All data variables depend solely on the altitude (either altitude or layer_center_altitude).