GABLS LES intercomparison

Case description
Model details
LEM data


GABLS LES Intercomparison

Case Description

The LES intercomparison case is based on the simulations of Kosovic and Curry (JAS, 2000, Vol 57, 1052-1068). The boundary layer is driven by an imposed, uniform geostrophic wind with a specifed surface cooling rate.

For the GABLS simulations, a domain of 400m × 400m × 400m was used with grid lengths ranging from 12.5m (coarser resolution) to 1m (high resolution). All the participants were able to perform at the coarser resolutions while only two centres provided the 1m grid length computations.

The geostrophic wind was imposed at 8 m/s at a latitude of 73o North (corresponding to f=1.39e-04). The inital potential temperature profile was 265K for 0m < z < 100m, increasing at 0.01K/m above. The field was given an initial perturbation of random noise with an amplitude of 0.1K on the potential temperature field for 0 < z < 50m. The surface cooling rate was specified as 0.25 K/h, with all simulations run out for 9 hours.

More information is given in the original instructions to participants.