Large-Eddy Simulation #125: Upwind PBL

LES RUN #125: Upwind PBL. This simulation was initialized horizontally homogeneous with a radiosonde sounding from the Sheboygan ISS during Lake-ICE on this morning of 13 Jan 98. Click here to see the NMSTASK file. This domain is 3 km (east-west) by 750 m (north-south) wide by 1.0 km tall and all over land with a roughness length of 10 cm. Periodic BCs in both horizontal directions. The flow is from the NW with a 400 m deep mixed layer. Radiation in the model is turned off and there is no surface heat flux.

This simulation is similar to LES104, except the domain is only 1 km tall (LES104 was 2 km tall). The shorter domain eliminates the simulation of levels above 1 km which cause gravity wave ducting. Since we use periodic lateral boundary conditions, this wave energy was trapped and the wave amplitude eventually grew so large that it strongly interfered with the mixed layer eddies (LES104). Here, in LES125, the waves are free to move vertically into a shallowing absorbing layer at the top of the model domain.

UW Lidar // Oct 10, 1999 //

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