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

vertical resolution

kgeorge

New member
Hello,

Could anyone please help in how to estimate the vertical resolution in meters (based on e_vert levels)? is it possible in the wrf? i use the pressure cordinate system and is it possible to cut a plane at a height of 100m by setting an eta level at that exact 100m height?

I am kind of a new user so i am confused with the vertical resolution, any help is so appreciated :)
thank you
 
wrfinput and wrfout files include the PH and PHB, the perturbation and base-state geopotential. You can derive the height of the vertical levels based on these two variables.

The vertical coordinate of WRF is hybrid terrain-following , and it is hard to set an eta level at exactly the 100m height.
 
Hello, I was trying to trying to put more values of eta layers between the first 1km but i have this cfl violation issue, can you please help me one more time ?
 

Attachments

  • Screenshot from 2023-07-08 15-47-24.png
    Screenshot from 2023-07-08 15-47-24.png
    2.6 MB · Views: 11
  • Screenshot from 2023-07-08 15-47-38.png
    Screenshot from 2023-07-08 15-47-38.png
    2.1 MB · Views: 10
CFL violation often indicates numerical instability. You can decrease time_step and turn on w_damping to overcome the CFL issue.
 
Dear ming chen,
thank you fr your reply, may i please know if it is ok if i use the timestep other than the 6 times dx , is it ok if it is lower than this? also, i had this violation of the cfl before and i turned off w_damping and then the simulation worked.. do you think it is normal?
 
The maximum time step is 6 x delx. However, you can always use time step smaller than 6 x delx.

It is 'normal' the model runs successfully with w_dmaping on or off. This option suppresses strong vertical velocity and increases the model stability.
 
Top