Spin-up Requirement for FCfireHIST Run with CLM5.0-BGC

[Junri]

Dear CESM community,

I have a question regarding the spin-up process for the FCfireHIST component using CAM60%CFIRE and CLM5.0-BGC in CESMv2.1.3. I am aiming to investigate fire-induced LAI changes. I’ve read in previous studies that when running CLM5.0-BGC with offline atmospheric forcing data, the spin-up process may require 200 to even 1000 years to reach carbon equilibrium.

I’m wondering if the FCfireHIST run also requires a similarly long spin-up period to achieve land carbon balance. Are there any recommended methods to shorten the spin-up process?

I would greatly appreciate any insights or suggestions.

Best regards,
Junri

 

[peverley]

I know this is an F compset, but I'm going to send this post over the the land group in the hopes that they have some insight.

 

[slevis]

I am not specifically familiar with the FCfireHIST compset, but the land biogeochemistry has the same requirements regardless of whether you run offline or coupled.

However, this is worth considering: If CAM's simulation has similar characteristics to the DATM meteorology of your offline simulations, then you may successfully shorten the bgc spin-up by completing it first offline and then proceeding with a shorter spin-up phase in coupled mode. I would not be surprised if others have tried and published with this approach before, so it's worth looking for examples elsewhere in the Forums and/or in the literature.

In the end of course, you as the scientist will decide what's satisfactory for your research.