Refactor Enrgy_sub, move all Enrgy_ functions

[BSchilperoort]

In STEMMUS_SCOPE.m, all Enrgy_ functions are called using the script Enrgy_sub:

STEMMUS_SCOPE/src/STEMMUS_SCOPE.m

Line 751 in d2fe0a6

run Enrgy_sub;

However, for model maintainability we want to remove all use of globals and running scripts.

Additionally, as all Enrgy_ functions seem to tackle one specific part of the model, these should be moved to a separate Matlab package with a appropriate name.

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To do:

• Move all Enrgy_ files to their own package, with an appropriate name
• Convert Enrgy_sub into a function. Use structures to reduce the amount of input and output variables.
• Add documentation to all functions
• Make the required changes in the main file.
• Create a pull request for the changes

[yijianzeng]

Thanks a lot, Bart, this would be great.

[SarahAlidoost]

@yijianzeng For each function below, please add one line explanation and suggest a better name in this issue, thanks

• Enrgy_sub
• EnrgyPARM
• Enrgy_MAT
• Enrgy_EQ
• Enrgy_BC
• Enrgy_Solve
• Enrgy_Bndry_Flux

[SarahAlidoost]

@yijianzeng please help to answer the question above. thanks

[yijianzeng]

• Enrgy_sub

This function is to solve the Energy balance equation with the Thomas algorithm ('Air_solve') to update the soil temperature ('TT'), the finite difference time-stepping scheme is exampled as for the soil moisture equation, which is derived in 'STEMMUS Technical Notes' section 4, Equation 4.32.

[yijianzeng]

• EnrgyPARM

This function calculates all the parameters related to energy balance equation (e.g., Equation 3.65-3.73, STEMMUS Technical Notes, page 29-32).

[yijianzeng]

• Enrgy_MAT

This function calculates all the parameters related to matric coefficients (e.g., c1-c7) as in Equation 4.32 (STEMMUS Technical Notes, page 44, which is an example for soil moisture equation), but here it is for energy equation.

[yijianzeng]

• Enrgy_EQ

This function assembles the coefficient matrices of Equation 4.32 (STEMMUS Technical Notes, page 44, the example was only shown for the soil moisture equation), but here it is for the energy equation.

[yijianzeng]

• Enrgy_BC

This function determines the boundary condition for solving the energy equation.

[yijianzeng]

• Enrgy_Solve

This function uses Thomas algorithm to solve the tridiagonal matrix equations, which is in the form of Equation 4.25 (STEMMUS Technical Notes, page 41)

[yijianzeng]

• Enrgy_Bndry_Flux

This function calculates the energy fluxes on the boundary nodes.

[SarahAlidoost]

While refactoring Enrgy_sub functions, I found two issues:

1. The variables calculated in these lines are unused in the model.
2. The function Enrgy_Bndry_Flux is used to calculate variables QET, QEB. However, they are unused in the model.
3. DDhDZ is not defined as InitialValues!

[yijianzeng]

1. The variables calculated in these lines are unused in the model.

Hi Sarah, this is ok, these lines are calculated, and can be put into output when requested. They are corresponding to Equation 3.9, and 3.10 in the STEMMUS technical note.

[yijianzeng]

2. The function Enrgy_Bndry_Flux is used to calculate variables QET, QEB. However, they are unused in the model.

The same, these are boundary fluxes calculated for any potential analysis, so could be deemed as model output and can be saved when requried.

[yijianzeng]

3. DDhDZ is not defined as InitialValues!

hI Sarah, is this initialized here