Scheduled Downtime
On Friday 21 April 2023 @ 5pm MT, this website will be down for maintenance and expected to return online the morning of 24 April 2023 at the latest

How to update a variable as the lower boundary condition, like what we do for SST


New member
Dear all,
I wanna update the sea surface roughness length z0 like what we do for sst using sst_update. what should I do? I search the "sst_update" string in the WRF code and have a preliminary understanding. To make things easier, I wanna update the z0 together with sst when we set the "sst_update=1". but I am still confused about how to combine the ZNT into the wrflowinp and read the znt from the file.
Can anyone give me some guidelines? I am grateful for your help.


You will need to have time-varying Z0, just like time-varying sst, in met_em files.

Then you will need to modify Registry.EM_COMMON, define z0 following the same way SST is defined, then run REAL. I suppose z0 should be included in wrflowinp file.

Please try and let me know if you have any issues.
thanks for your reply. I can not find the SST in the Registry.EM_COMMON, only skin SST, but i see the SST exists in the wrfinput and wrflowinp. it confuses me:ROFLMAO: i found the SST in the Registry.EM. Should i define the Z0 in this file?
SST is defined in Registry.EM:
state real SST ij misc 1 - i01245rh0d=(interp_mask_field:lu_index,iswater) "SST"
I got it. Z0 also appears as ZNT in the Registry.EC_COMMN, does it need to be commented out? or i should keep it