LITFASS-2003

Purpose

This example shows the development of the convective boundary layer in the presence of irregular distributed surface heterogeneities in the LITFASS region on two days (May 30 and June 13, 2003).

Description

The example was generated in the course of the LITFASS-2003 project (details). The LITFASS area is heterogeneous and includes several land use classes such as forest as well as agricultural regions, grassland and lakes. Each land use class has its own characteristics concerning temperature, humidity, roughness and surface fluxes. The developing boundary-layer shows signals of this heterogeneity all day long. The simulations start in the early morning, when no turbulence is present (05 UTC) and ends with the evening transition (17 UTC). Results from this simulation were published in Maronga and Raasch (2013).

References

• Maronga, B. and S. Raasch, 2013: Large-Eddy Simulations of Surface Heterogeneity Effects on the Convective Boundary Layer During the LITFASS-2003 Experiment. Boundary-Layer Meteorol., 146:17-44, doi: ​10.1007/s10546-012-9748-z
  

PALM version

r893

Required user code

Please find the user code attached​.

Parameter files

Parameter files are available for May 30​ and June 13​.

Preprocessing

Surface data are required (see surface data for May 30​ and surface data for June 30​) and must be placed in a directory that is accessible for the host on which PALM is executed (remote host). Modify the userpar parameter input_path to point to this directory.

Model run

The basic command is

mrun -d LITFASS-2003 -r "d3# ts# pr# xy# 3d# restart" -T 8 -t 10800 -X 64

for May 30 and

mrun -d LITFASS-2003_13_june -r "d3# ts# pr# xy# 3d# restart" -T 8 -t 10800 -X 64

for June 13.

Please set other options, such as -h, -K, and -q according to your needs. Note that this example will require 64 processors for at least two hours. If you want to carry out this job with less processors, please adjust the parameter file. You can also carry out restarts.

Monitoring

Please find the run control file (for May 30 only) attached​.

Postprocessing

Studying the boundary layer in the LITFASS region, you will notice, that secondary circulations develop the course of the day. You can for example see such structures in the time-averaged 3D data. Please note, however, that a time-average is not sufficient to completely separate the secondary circulations from the turbulent flow and an additional ensemble average is required to achieve this.