Scheduled Downtime
On Tuesday 24 October 2023 @ 5pm MT the forums will be in read only mode in preparation for the downtime. On Wednesday 25 October 2023 @ 5am MT, this website will be down for maintenance and expected to return online later in the morning.
Normal Operations
The forums are back online with normal operations. If you notice any issues or errors related to the forums, please reach out to help@ucar.edu

Question about the tridiagonal matrix solution

jinmuluo

Jinmu Luo
Member
where x is unknown.
Hi Keith,

Thank you so much for your quick reply.
I have a follow-up question about the module : soilbiogeochem/SoilBiogeochemLittVertTranspMod.F90
If I understand correctly, what this module wants to do is to build a vertical mixing matrix A which is based on the vertical concentration gradient to update the CN vertical concentration, for example, to predict the vertical mixing of the soil carbon in the next time step, C(t+1) = A*C(t).
Do you think the TridiagonalMod.F90 module satisfies this purpose? If I misunderstood anything, please let me know, I have been stuck here for a while.

Best,
 

oleson

Keith Oleson
CSEG and Liaisons
Staff member
I believe so. There isn't documentation in the technical note that documents this approach in detail for vertical mixing of carbon, but something similar is done for soil temperature. See Chapter 6:


In particular, equation 2.6.12 describes the set of equations for soil temperature in which T(n+1) is the soil temperature at the next time step n+1, r is the "forcing term", and a,b,c are the subdiagonal, diagonal, and superdiagonal elements.
 

jinmuluo

Jinmu Luo
Member
I believe so. There isn't documentation in the technical note that documents this approach in detail for vertical mixing of carbon, but something similar is done for soil temperature. See Chapter 6:


In particular, equation 2.6.12 describes the set of equations for soil temperature in which T(n+1) is the soil temperature at the next time step n+1, r is the "forcing term", and a,b,c are the subdiagonal, diagonal, and superdiagonal elements.
Hi Keith,

Thank you so much for that, I've now noticed the differences. I guess the Litter transport module also used the Crank-Nicholson method and the alpha is zero in this module (alpha in the formula 2.6.11), the same thing for the soil water module.

Best,

Jinmu
 
Top