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

Change in Mandatory Static Data


New member
Hello WRF community,

I am running a simulation with two domains: d01 with 9km resolution and d02 with 3km. In the near future I will add a d03 with 1km resolution.

Previous studies in the region of my domain show that changing the default WPS topography to ASTER with a resolution of 1s (90 meters), results in an improvement in the ability of WRF to simulate surface winds, which is my purpose. Given this knowledge, I changed the default topography to ASTER_1s. My configuration uses YSU as PBL and now I will try the topo_wind=1 and 2 options, but from the thread [1], I am wondering:

Should I change the VAR_SSO database to an ASTER one? I don't know if ASTER has this variable, but I can calculate it, convert it to binary, and then add it to GEOGRID.TBL. The other option is to use the VAR_SSO available in 30s resolution (WPS-4.2).

What do you recommend?
Is there another variable (e.g. VAR_SSO) that I should change?

[1] (RESOLVED) Problems with different resolution Mandatory Static Data
Last edited:
There are a few issues here:

(1) what is your resolution? Note that even if you use 90m topography data as input, if your grid interval is, for example 3km, then the 90m topography data will be averaged over the 3km grid cell, and the effect is a smoothing 3km topography ( more or less equivalent to 3km topography data).

(2) var_sso is the topography variance that is used to "correct" surface winds over complex terrrain area, i.e., when you turn on topo_wind option, you will need var_sso as input. Again, whether or not you need to create var_sso for the 90m topography depends on the resolution of your case.

(3) At 90m resolution, the model will switch to LES mode, and PBL scheme should be turned off. However, topo_wind option can only work when the YSU PBL scheme is turned on.
Thanks for the quick reply.

I am running a simulation with two domains: d01 with 9km resolution and d02 with 3km. I will add a d03 with 1km resolution soon. I do not need switch to LES mode.

(1) There is a study that demostrated that change the elevation model product from GMTED_30s to ASTER_1s, results in improvements in the abilities of WRF to simulate surface wind in my domain (south of south america a region with complex topography). This is because GMTED_30s have somes gaps at this region.

So, should I calculate VAR_SSO from ASTER to be consistent with the new topography that I am using?