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<TITLE>Experiences with high-resolution WRF-ARW</TITLE>
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<P><FONT SIZE=2>Dear wrf-users:<BR>
<BR>
My group is running WRF-ARW at high resolution (dx = 1 km) to simulate turbulence. <BR>
Recently we tried running at very high vertical resolution (dz ~= 12.5 m in the lowest<BR>
500 m of the domain), and encountered CFL errors with time steps as<BR>
low as 1/8 of a second. These runs used the 6th order diffusion<BR>
option from Knievel et al (2007), along with real terrain (area around<BR>
Albuquerque, NM) and physics (MYJ TKE, Noah land surface,<BR>
RRTM/Dudhia radiation, and WSM5 microphysics).<BR>
<BR>
Has anyone here run WRF at such fine resolution, and if so, what were<BR>
your experiences with the time step? The ARW documentation recommends<BR>
6 seconds for each kilometer of dx, ignoring the effect of vertical resolution. <BR>
Are there other settings that should be tuned?<BR>
<BR>
-Eric<BR>
<BR>
Eric M. Kemp<BR>
Meteorologist<BR>
Northrop Grumman Information Technology<BR>
Intelligence Group (TASC)<BR>
4801 Stonecroft Boulevard<BR>
Chantilly, VA 20151<BR>
(703) 633-8300 x7078 (lab)<BR>
(703) 633-8300 x8278 (office)<BR>
(703) 449-3400 (fax)<BR>
eric.kemp@ngc.com<BR>
<BR>
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