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<P><FONT SIZE=2>Eric,<BR>
<BR>
The model levels are determined in subroutine compute_eta, located in WRFV3/dyn_em/module_initialize_real.F.<BR>
<BR>
-Eric<BR>
<BR>
Eric M. Kemp<BR>
Meteorologist<BR>
Northrop Grumman Information Systems<BR>
Security and Systems Engineering 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>
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<BR>
<BR>
-----Original Message-----<BR>
From: wrf-users-bounces@ucar.edu on behalf of Eric Altshuler<BR>
Sent: Sat 1/10/2009 1:07 AM<BR>
To: wrf-users<BR>
Subject: Re: [Wrf-users] default sigma level settings<BR>
<BR>
Hello Jorge,<BR>
<BR>
I think the point of the original question was this: What are the sigma levels chosen by default when eta_levels is NOT specified? Suppose I set e_vert = 41 but don't specify eta_levels. What is the resulting distribution of sigma level values? There must be some formula in the code that calculates the 41 sigma values in this case, but it isn't clear how the default levels are calculated for a given value of e_vert.<BR>
<BR>
Best regards,<BR>
<BR>
Eric L. Altshuler<BR>
Assistant Research Scientist<BR>
Center for Ocean-Land-Atmosphere Studies<BR>
4041 Powder Mill Road, Suite 302<BR>
Calverton, MD 20705-3106<BR>
USA<BR>
<BR>
E-mail: ela@cola.iges.org<BR>
Phone: (301) 902-1257<BR>
Fax: (301) 595-9793<BR>
<BR>
----- Original Message -----<BR>
From: "Jorge Alejandro Arevalo Borquez" <jaareval@gmail.com><BR>
To: "anis 980" <anis_980@sina.com><BR>
Cc: wrf-users@ucar.edu<BR>
Sent: Thursday, January 8, 2009 12:37:39 PM GMT -05:00 US/Canada Eastern<BR>
Subject: Re: [Wrf-users] default sigma level settings<BR>
<BR>
Hi,<BR>
In WRF you can give explicitly the values for vertical levels, to do this<BR>
you need add eta_levels values like this:<BR>
<BR>
&domains<BR>
eta_levels = 1.0000, 0.9960, 0.9940, 0.9920, 0.9900,<BR>
0.9880, 0.9850, 0.9820, 0.9780, 0.9740, 0.97, 0.965,<BR>
0.96, 0.949, 0.937, 0.924, 0.909,<BR>
0.892, 0.873, 0.851, 0.826, 0.798,<BR>
0.768, 0.736, 0.702, 0.666, 0.629,<BR>
0.5915, 0.5536, 0.5153, 0.4773, 0.44,<BR>
0.404, 0.3695, 0.3375, 0.3085, 0.2845,<BR>
0.2645, 0.2465, 0.2305, 0.2165, 0.2035,<BR>
0.1915, 0.1792, 0.1667, 0.1539, 0.1407,<BR>
0.1272, 0.1134, 0.0995, 0.0855, 0.0713,<BR>
0.0571, 0.0520, 0.0480, 0.0429, 0.038,<BR>
0.032, 0.0287, 0.022, 0.018, 0.0145, 0.007, 0.000,<BR>
time_step = 200,<BR>
...<BR>
...<BR>
<BR>
<BR>
Best regards<BR>
<BR>
2008/12/25 <anis_980@sina.com><BR>
<BR>
> Hello,<BR>
> I am trying to run WRF ideal case em_quarter_ss, and I set "s_vert=1,<BR>
> e_vert=41 " in namelist.input file. But I want to know the sigma value of<BR>
> each level, does anyone know how does WRF model generate sigma values<BR>
> according the total number of vertical levels? What is the default sigma<BR>
> value according vertical level settings?<BR>
> Best,<BR>
> Leo<BR>
><BR>
> _______________________________________________<BR>
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><BR>
><BR>
<BR>
<BR>
--<BR>
Atentamente<BR>
Jorge Arévalo Bórquez<BR>
<BR>
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