[Biogenics] Adding parametrized Soil Moisture and Nitrogen Processes to Canopy-App

[quaz115]

Start with Parametrized BDSNP soil NO scheme as in HEMCO (https://github.com/geoschem/HEMCO/blob/main/src/Extensions/hcox_soilnox_mod.F90) or MEGAN v3.2

ENOx = f( T, biome, WFPS, Fert) x Pulse(dryspell) x canopy uptake

Can utilize MEGAN v3.2 soil NO input data for this

Note: Soil NH3 volatilization schemes would need soil NH4+ (example: [DNDC model] https://www.sciencedirect.com/science/article/pii/S0048969718353038)), eventually would need a mechanistic option that distinguishes the total soil Nitrogen in to organic and inorganic pools (NH4 and NO3)

[drnimbusrain]

@quaz115 Great talking to you yesterday, and this is awesome if you can take the lead here!

A few comments/suggestions:

1. I agree we can start with adding MEGANv3.2 soil NO input data from here, and that we would want to add this to the global python script that downloads GFS met data, calculates/adds other needed variables, and adds climatological canopy variables from satellite. Obviously other soil data from the GFS model inputs will need to be added, but things like precip, soil temp, and soil moisture are available in the GFS sfc files used here. Understood as the mechanisms get more complex we will likely need other soil data inputs as you suggest (NH4+), and we want this to have global extent for canopy-app (maybe more challenging).
2. As you add the soil NO option, its best to follow the format/structure of how canopy-app is built, such as adding a new option to turn this on/off as needed (e.g., "ifcansoilN" or "ifcansoilNO"). Of course, soil processes and output diagnostics may interact differently with the canopy thresholds compared to turning on the explicit canopy processes, but canopy-app can be modified to handle the soil NO differently in this respect, where the contiguous canopy thresholds in canopy-app can control things like the needed canopy reduction factors for soil NO fluxes to the atmosphere.
3. Furthermore, as you start with the BDSNP scheme and add mechanistic schemes later, its best to follow canopy-app structure and add flexibility to switching between schemes as has been done for other options (e.g., "soilNO_opt") and tuning parameters (if needed).
4. Ultimately, this effort begins to address and cross-over to the larger issue of "Adding Biogeochemical Carbon/Nitrogen Fluxes in issue #65 , so its great that you are working on this aspect heading towards a canopy-appv1 and paper!

[drnimbusrain]

@quaz115 @MaggieMarvin Also here, we would want to take the opportunity to add in a Soil moisture emission activity factor (γSM), which can be estimated as a function of soil moisture and wilting point (see Guenther et al. 2006): https://acp.copernicus.org/articles/6/3181/2006/acp-6-3181-2006.pdf