improver.uv_index module
Module for calculating the uv index using radiation flux in UV downward at the surface.
- calculate_uv_index(uv_downward, scale_factor=3.6, model_id_attr=None)[source]
A plugin to calculate the uv index using radiation flux in UV downward at the surface and a scaling factor. The scaling factor is configurable by the user.
- Parameters:
uv_downward (
Cube) – A cube of the radiation flux in UV downward at surface. This is a UM diagnostic produced by the UM radiation scheme see above or the paper referenced for more details.(W m-2)scale_factor (
float) – The uv scale factor. Default is 3.6 (m2 W-1). This factor has been empirically derived and should not be changed except if there are scientific reasons to do so. For more information see section 2.1.1 of the paper referenced below.model_id_attr (
Optional[str]) – Name of the attribute used to identify the source model for blending.
- Return type:
- Returns:
A cube of the calculated UV index.
- Raises:
ValueError – If uv_downward is not named correctly.
ValueError – If uv_downward contains values that are negative or
not a number. –
References
Turner, E.C, Manners, J. Morcrette, C. J, O’Hagan, J. B, & Smedley, A.R.D. (2017): Toward a New UV Index Diagnostic in the Met Office’s Forecast Model. Journal of Advances in Modeling Earth Systems 9, 2654-2671.