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ajwdewit / pcse

Repository for the Python Crop Simulation Environment
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Need for Angstrom factors even if HasSunshine=False #75

Closed glemoine62 closed 1 year ago

glemoine62 commented 1 year ago

I provide IRRAD values derived from ERA5 SiS Agmet daily solar_radiation_flux and (therefore) set HasSunshine=False, also because I do not know the Angstrom factors for my particular area (so I filled in dummies, because they are still required). However, pcse still checks these factors, so they must obey the validity range. The check should depend on HasSunshine. (I use CSVWeatherDataProvider)

Minor nuisance.

ajwdewit commented 1 year ago

Hi Guido,

Thanks for your remark and I agree that the need to have the Angstrom coefficients is a bit of nuisance. However, your remark is not entirely true, the Angstrom equation is used in the Penman equation here: https://github.com/ajwdewit/pcse/blob/master/pcse/util.py#L183 Although we do not rely on the Penman equation for the crop reference ET, we still use if for the bare soil ET and open water ET.

Nevertheless, I will have a look at it to see if there are alternative formulations of the Penman equation that do not require the Angstrom A/B parameters.

Allard