Unrealistic negative/positive values for the Turch equation at sub-freezing temperatures

pyet-org / pyet

:sunflower: pyet is a Python package to estimate reference and potential evaporation.

https://pyet.readthedocs.io/

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Unrealistic negative/positive values for the Turch equation at sub-freezing temperatures #47

Closed mvremec closed 1 year ago

mvremec commented 1 year ago

The Turc equation generates unrealistic results when the mean daily temperature falls below 0 degrees Celsius. The lower the temperature, the more unrealistic the results become. Although I was not able to find any literature indicating that the Turc equation should not be used in subfreezing temperatures, I plan to set PET equal to 0 when the mean temperature is less than 0 degrees Celsius.

PET = 0, if tmean < 0.

Many thanks to Jannis for this heads-up!

mvremec commented 1 year ago

It should be fixed in the developer branch.