BBL modeling

Question

Hi Chris,

Can you please clarify how is the bottom boundary layer modelled depending on the selected "DEFAULT_BC" and "iclosure"? When iclosure=6 (mixing layer model), the model seems insensitive to "drag_btm_cd", regardless of the selected "DEFAULT_BC". Is "mixing_coeff_cb" the parameter that can modify the BBL energy budget (via eq. 6.4. in the new AEM3D Science Manual) for iclosure=6? Thank you.

Cheers,

Andres

Answer 1

Hi Andres,

The key parameter to set in run_Aem3d for BBL mixing is ibblmixing. Set this to one.

Without this bottom energy is generated and added to the bottom cell of each column but is only used in mixing of the bottom two cells.  WIth ibblmixing switched on there is an additional upsweep of TKE mixing.

Chris