Large-Eddy Simulation #224: (Upwind)

LES RUN #224: Upwind simulation. Shear driven. 200 x 120 x 69 with 15-m resolution in all 3 directions. Periodic lateral boundary conditions. Entire domain over snow-covered land. Arakawa & Lamb advection routine, VDKR=HDKR=0.05. Horizontally homogeneous initial condition according to observations. The initial temperature and dew-point profile was from the radiosonde and the initial wind speed and direction profiles were from linear fits to the data as shown in the first frame of the animation (the thumbnail is the last frame of the animation.) Click here to see the NMSTASK file of LES #224.

The following animation shows the evolution of mean profiles (red lines) of wind speed, direction, temperature and dewpoint as well as vertical velocity on a east-west oriented vertical slice.

Problems with this simulation: 1) The surface dew-point is incorrect and T and Td data below 200-m were not included in the initial condition. 2) The winds below 400 m were fit with a single sloping line. A better fit might be to have a seperate slope for the entrainment zone (300-500 m) and constant speed & direction below 300.

UW Lidar // Dec 7, 2000 //

Return to the Index