Is Soil Moisture in WRF time varying?

[Liliputian_123]

Dear WRF experts,

I am a bit confused how the WRF model is reading soil moisture data.

I am running WRF using GFS as ICBC. The met_em fils contains soil moisture (for four layers and for different time periods).
But, in the wrfinput file, there is a variable SMOIS but has only one time step (not varying in time).

I would like to know:
1. Is it possible to run WRF with time-varying soil moisture data? (e.g., use GLDAS data). If yes, how can I do this in WRF?
2. How is soil moisture integrated in the WRF model? Is this independently called by the LSM model?
3. How does WRF combine the time varying soil moisture from the met_em files to a single SMOIS variable in the wrfinput file?

According to this thread: Setting soil moisture to 0% and 100% in the WRF-ARW model
The SMOIS is predicted by the LSM in the WRF model once running. So what is the SMOIS in the wrfinput file? just the SMOIS at the initialization time or was this a combination of the soil moisture at different times?


I'll appreciate any help on this.
Thank you!

 

[haiqingsong]

WRF reads soil moisture from the first met file, and then the soil moisture will be forced by WRF variables only.

 

[Ming Chen]

Dear WRF experts,

I am a bit confused how the WRF model is reading soil moisture data.

I am running WRF using GFS as ICBC. The met_em fils contains soil moisture (for four layers and for different time periods).
But, in the wrfinput file, there is a variable SMOIS but has only one time step (not varying in time).

I would like to know:
1. Is it possible to run WRF with time-varying soil moisture data? (e.g., use GLDAS data). If yes, how can I do this in WRF?

WRF doesn't have this capability.

2. How is soil moisture integrated in the WRF model? Is this independently called by the LSM model?

Soil mousture is a pronostic variable in LSM model.

3. How does WRF combine the time varying soil moisture from the met_em files to a single SMOIS variable in the wrfinput file?

WRF only reads soil information (temperature and moisture) at the initial time.

According to this thread: Setting soil moisture to 0% and 100% in the WRF-ARW model
The SMOIS is predicted by the LSM in the WRF model once running. So what is the SMOIS in the wrfinput file? just the SMOIS at the initialization time or was this a combination of the soil moisture at different times?

SMOIS in wrfinput is derived from large scale forcing data, e.g., GFS, ERA5, etc. It is the data at the initial time. There is no combination of soil data at different times.

I'll appreciate any help on this.
Thank you!

 

[Liliputian_123]

Thank you all for the response! I learned a lot!