"2006-09-26 18:12:43.0" . . "" . "2006-09-26 18:12:43.0" . "SDN:P07::CFSN0450" . "'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."@en . . . . "SDN:P07::CFSN0450" . "accepted"@en . "false" . . "SDN:P07::CFSN0450" . . "1" . "potential_vorticity_of_atmosphere_layer"@en . . . "1" . . .