Some questions about modifying snow water on CLM4.0

[Zcheng]

大家好，

I'm conducting a resemble experiment regarding snow water accumulation (Compset: F_AMIP_CAM5). In the land module restart (.r) file that I'm using for the experiment, I directly increased the snow water equivalent (variable: H2OSNO) by 10 mm for values greater than 100 mm and running the model by using the branch method. However, this modification resulted in a water balance error on CLM model (first line of the picture). The error message indicates that the error is greater than 0.1. I don't know how to modify it correctly so I‘m reaching out here to seek assistance. I have provided the key error information and the complete cesm.log.

任何建议将不胜感激。

 

[Zcheng]

cesm.log

 

[slevis]

The branch method that you used can handle very limited changes, for example you could make changes to history files. A similar but more flexible choice is the hybrid method. Even simpler is the startup method. With either one of these methods, you should be able to start the simulation with the modified restart file and not get an error.

 

[Zcheng]

The branch method that you used can handle very limited changes, for example you could make changes to history files. A similar but more flexible choice is the hybrid method. Even simpler is the startup method. With either one of these methods, you should be able to start the simulation with the modified restart file and not get an error.

Thank you for your reply. I tried the hybrid method, and it did work indeed. However, I'm not sure why the branch method is causing an error. I would like to ask, what is the difference between these two?

 

[oleson]

There is information on the difference between these in your env_run.xml (see RUN_TYPE).