[gradsusr] plotting wind speed (or velocity) versus height rather than level number

[John D. Wilson]

Hi Ron,

I'd been using "set z 1 45" (for instance). It never occurred to me I 
could specify in mb. However I've just now tried

set x 38
set y 38
set z 1000 900
d ugrdhlev

and got

Data Request Error: Invalid grid coordinates
   Varying dimension 2 decreases: 1000 to 900
   Error ocurred getting variable 'ugrdhlev'
   Error ocurred at column 1
DISPLAY error:  Invalid expression
   Expression = ugrdhlev

This is even though q ctlinfo returns

ugrdhlev  58  0,2,2  ** (58 57 56 55 54.. 5 4 3 2 1) U-Component Of Wind 
[m/s]


I also tried specifiying an interval for z in Pa -- similar complaint. John.

On 17/07/13 18:02, Goodson,Ron [Edm] wrote:
> Hi John
>
> If you original levels were in pressure or height or sigma .. then I'm surprised it doesn't plot that as the vertical coord (if that is what you meant). Pretend the vertical coord is in mb in your original data.  Did you do something like "set z 1 10" or did you do "set z 1000 500".  The latter should cause the vertical coord to be mb.
>
>
> If, however, you actually want all those different coord systems, then you will have to interpolate U to the various levels you want .. using something like the grads-script "zinterp.gs" (in the script library)
>
>
> Ron Goodson		
> Prairie and Northern Meteorological Service of Canada Science Section	Unité des Sciences, Région des Prairies et du Nord, Service Météorologique du Canada	
> Environment Canada
> Room 200 ; 4999 - 98 Avenue
> Edmonton Alberta T6B 2X3	Environnement Canada
> Pièce 200 ; 4999 - 98 Avenue
> Edmonton Alberta T6B 2X3	
> Telephone | Téléphone	780 951 8791	
> Email | Courriel	ron.goodson at ec.gc.ca	
>
>
>
> -----Original Message-----
> From: gradsusr-bounces at gradsusr.org [mailto:gradsusr-bounces at gradsusr.org] On Behalf Of John D. Wilson
> Sent: July 17, 2013 4:42 PM
> To: gradsusr at gradsusr.org
> Subject: [gradsusr] plotting wind speed (or velocity) versus height rather than level number
>
> Hi,
>
> I'd like to plot a wind profile at fixed (X,Y,t). It's straightforward to plot (for instance) the u-component versus level number (``d
> ugrdhlev'') but I'd like instead to display u versus height, or u versus pressure, or u versus sigma. I expect this is really easy but I haven't yet stumbled on the trick. Can anyone help? Thanks, John _______________________________________________
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-- 
J.D. Wilson (Prof)
Rm. 3-277, CCIS Building
Department of Earth & Atmospheric Sci.
University of Alberta, Edmonton, AB T6G2E3
780 492 0353