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usa-npn / cales-thermal-calendars

Estimating trends in phenology in the northeastern US
https://usa-npn.github.io/cales-thermal-calendars/spatial-trends-report.html
MIT License
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Nail down method for calculating GDD #16

Closed Aariq closed 5 months ago

Aariq commented 6 months ago

Apparently there are 16 methods to to calculate GDD! We should pick one

Aariq commented 6 months ago

The Baskerville-Emin method was suggested as the one to use:

https://esajournals.onlinelibrary.wiley.com/doi/abs/10.2307/1933912 https://www.canr.msu.edu/uploads/files/Research_Center/NW_Mich_Hort/General/CalculationBaskervilleEminGDD.pdf

Aariq commented 6 months ago

@diazrenata if you feel like you have bandwidth to take a shot at translating this method into code while I'm trying to get things working on the HPC, feel free to make a PR. The relevant function is here: https://github.com/usa-npn/cales-thermal-calendars/blob/d2185dfdff39f5ea1166d8c5ed197905d036fcba/R/calc_gdd_doy.R#L40

(although if we need both tmin and tmax instead of just tmean, we'll also need different data from PRISM)

Aariq commented 6 months ago

Ok, took a quick look and seems like if we go with this method we will need tmin and tmax rather than just tmean. I'll open a separate issue for downloading these data.

Aariq commented 5 months ago

Simple averaging it is!