Large-Eddy Simulation #195: (IBL)
LES RUN #195: This was an attempt to duplicate & compare with LES #181 but
with just two improvements: 1) the grid is 300-m taller by stretching the cells
above 675 m, and 2) the passive tracer is restored to the initial profile
in the restoring zones.
But, after run #181, we implemented an Arakawa & Lamb advection routine that
was used on #195. This new scheme has improved conservation properties by
implementing a 3-D averaging procedure designed to maintain better
momentum conservation and three-dimensional consistency.
The effect is to eliminate spurious 3-D small-scale rolls that developed
over the land resulting from the Sadourney scheme.
See figure below.
The following two images show the pressure-perturbation at 3288 s after
initialization on vertical and horizontal planes. Contours on the
vertical slice are of potential temperature. The zero-isoline of
pressure perturbation is shown for clarity on the horizontal slice.
This simulation was
run out to 3300 s (50-minutes) past initialization and terminated.
LES #196 is being run to resume where this left off, and it has the
single row of random wiggles turned back on.
This simulation took 18-days to run on our j50.
Click here
to see the NMSTASK file of LES #195.
The following is a horizontal slice through the bottom of the model domain
(7.5 m above the surface) over the water only. The output has been folded over once in the
north-south direction to help your eye follow coherent structures across
the domain. This is an east-west subset of the model domain.
The following is an east-west vertical slice through the model domain.
The following is a horizontal slice through the bottom of the model.
The entire area is shown.
The following is the same horizontal slice as above, but for LES#181.
UW Lidar // June 13, 2000 // root@lidar.ssec.wisc.edu
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