Questions about "nens" in stochastic parameterizaion schemes

[semin]

Hi, I'm WRF model newbie.

I'm running WRF model with 3 domains and I chose the physics suites named NCAR Convection-Permitting Suite.
And I added the option Stochastic parameterization schemes.

This is part of my namelist.input

 &stoch
 rand_perturb                        = 1,   1,   1,
 nens                                = 1,
 skebs                               = 1,   1,   1,
 nens                                = 1,
 /

When I run WRF with this namelist.input, it looks working.

I want to increase the number of ensemble members, and to do that I need to change the "nens" in namelist.input to 2,3,4,... each time I run the model.
and then run ./real.exe and ./wrf.exe?

And are the "nens" under "rand_perturb" different from the "nens" under "skebs"?

If I want to run the model again, can I change the namelist.input like this and then run it?

 &stoch
 rand_perturb                        = 1,   1,   1,
 nens                                = 2,
 skebs                               = 1,   1,   1,
 nens                                = 2,
 /

 

[kwerner]

Hi,
Both occurrences of 'nens' you have in the namelist are the same parameter. The second one is just a duplicate entry, so you can remove it. If you need to change nens to =2, yes, you can change it and run again.

 

[semin]

Thanks for the reply, can I change nens to =2 and skip real.exe and just run wrf.exe? Or do I need to run both?

 

[kwerner]

I believe it should be okay, but just test it and look at your output to make sure it looks reasonable.

 

[semin]

Thanks, I'll try it.