Snow surface temperature parameterization

[kmdeck]

Purpose

Adds the parameterization that @sarahhzhangg developed for snow surface temperature

To-do

This currently gives some poor results - is this due to snow depth being incorrect?
Make this an optional parameterization using Julia structs
Rebase after Andy's snow depth model is merged into main

Address other questions:
Using snow_thermal_conductivity instead of kappa_ice seems to overall worsen the model performance (based on RMSE, although it improved cdp temperature RMSE a bit)
Might be better to use kappa_ice in the rebased version?
The stability issue seems to be gone (runs for snb)
It seems like your rebased version inputs FT(0) instead of h_sfc (line 331)
Does it matter what is used as the initial guess (Tair vs Tbulk) in the root solver?
Is the removal of runoff energy from the fluxes (Fh) intentional?

Content

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