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 change minimum PBL mixing coefficient [m^2 s^-1] within the MYNN2 scheme?

This post was from a previous version of the WRF&MPAS-A Support Forum. New replies have been disabled and if you have follow up questions related to this post, then please start a new thread from the forum home page.


New member
Hi all,

I would like to conduct some sensitivity runs by modifying the minimum PBL mixing coefficient [m^2 s^-1] within the MYNN2 PBL scheme.

Does anyone know how to do it in the code/namelist?

Thank you in advance!


This post has been moved to the 'WRF Physics' section of the forum, as this pertains specifically to physics. Someone will respond to your inquiry soon.
Hi Caterina,
The mixing coefficients for momentum, temperature and moisture are computed in subroutine mym_turbulence in module_bl_mynn.F, and the variables are dfm, dfh and dfq. Note that these are divided by dz, so the unit is just m/s. There is a note at the top of the subroutine that states this.