improver.cli.gradient_between_vertical_levels module#
CLI to calculate a gradient between two vertical levels.
- process(*cubes)[source]#
Calculate the gradient between two vertical levels. The gradient is calculated as the difference between the input cubes divided by the difference in height.
Input cubes can be provided at height or pressure levels. If the cubes are provided at a pressure level, the height above sea level is extracted from height_of_pressure_levels cube. If exactly one of the cubes are provided at height levels this is assumed to be a height above ground level and the height above sea level is calculated by adding the height of the orography to the “height” coordinate of the cube. If both cubes have height coordinates no additional cubes are required. It is possible for one cube to be defined at height levels and the other at pressure levels.
- Parameters:
cubes (iris.cube.CubeList) – Contains two cubes of a diagnostic at two different vertical levels. The cubes must either have a height coordinate or a pressure coordinate. If only one cube is defined at height levels, an orography cube must also be provided. If either cube is defined at pressure levels, a geopotential_height cube must also be provided.
- Returns:
A single cube containing the gradient between the two height levels. This cube will be renamed to “gradient_of” the cube name and will have a units attribute of the input cube units per metre.
- Return type: