|Description||"Layer" means any layer with upper and lower boundaries that have constant values in some vertical coordinate. There must be a vertical coordinate variable indicating the extent of the layer(s). If the layers are model layers, the vertical coordinate can be model_level_number, but it is recommended to specify a physical coordinate (in a scalar or auxiliary coordinate variable) as well. Atmosphere potential vorticity is the vertically averaged absolute vorticity of a layer of the atmosphere divided by the pressure difference from the bottom to the top of the layer.|
|AMIP code (Library of AMIP Data Transmission Standards)||not specified|
|GRIB code||not specified|
The parameter was taken from the NetCDF CF Metadata Convention.