DYCOMS

Purpose

With this example stratocumulus-topped boundary layers can be studied.

Description

The setup is based on the ​GCSS LES intercomparison case ​DYCOMS-II-RF01 (​Stevens et al. (2005)). It describes stratocumulus convection in the sub-tropics over the ocean. With PALM, a well-mixed, coupled boundary layer with a continuous cloud deck can be simulated. Results from DYCOMS simulations with PALM were published in Heinze et al., (2012).

References

• Heinze, R., S. Raasch and D. Mironov, 2012: Budgets of scalar fluxes for cloudy boundary layers
  20th Symposium on Boundary Layers and Turbulence, Boston, MA, USA (talk) ​extended abstract
  
  

PALM version

r995

Required user code

Please find the user code attached​. The DYCOMS case requires a special radiative forcing which is contained in calc_radiation_dycoms.f90. Due to this radiation scheme, small adjustments in the Makefile and in prognostic_equations.f90 are necessary. Additionally, prandtl_fluxes.f90 has to be slightly modified. The files mentioned before can be found in the attachment user_code​ in addition to the user routines. All the files in the attachment​ have to be placed in the same directory as the user routines.

Parameter files

Please find the parameter file attached​.

Model run

The basic command is

mrun -d dycoms -r "d3# ts# pr# xy# 3d#" -X 128 -T 8 -t 14400

Please set other options, such as -h, -K, and -q according to your needs. Note that this example will require 128 processors for at least 3 hours. If you want to carry out this job with less processors, please adjust the parameter file accordingly.

Monitoring

Please find the run control file attached​.

Postprocessing

The results of the simulation are in accordance with the results of most of the other LES models which took originally part in the LES intercomparison. For a quantitative comparison, the LES data of the models is available ​here.