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20000909: Zonal Wind Plot

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  • Subject: 20000909: Zonal Wind Plot
  • Date: Fri, 15 Sep 2000 15:15:27 -0600
Daryl,

I have tried to duplicate your problem, but basically can't duplicate your 
problem. First, let me make sure you are using a CED grid, otherwise
XAV which is the average along a grid row will not be along a constant
latitude (and therefore will change with your cxstns longitude position).

I tested using the global AVN thinned grid. And ran for:
cxstns = -80;150>80;150
cxstns = -80;-150>80;-150
cxstns = -80;-30>80;-30

Basically, all the contours aligned- except for a few small variations
for wiggles in the 0 line between east and west zonal winds. I presume 
that you are seeing much greater differences. Or is this the type of 
discrepancy you are seeing?

I believe the wiggles I am seeing around 0 are roundoff errors in interpolating 
from the CXSTNS lat/lon values to the projected grid point locations amd
then gridding these for the x-z display.

If you are seeing greater difference in the complete pattern, then it would
help me to know what the grid projection you are using is, the source of the 
data,
and if possible, a gif image of the variations overlaid.

Steve Chiswell
Unidata User Support




>From: Daryl Herzmann <address@hidden>
>Organization: UCAR/Unidata
>Keywords: 200009090542.e895g1b07934

>Hello All,
>       I have been trying to create a cross-section plot of the zonal
>wind averaged over all longitudes.  The plot would look like the classic
>zonal wind plots in textbooks, showing the jets.  Anyway, the problem is
>that I can not seem to get an average using gdcross.  The variable CXSTNS
>seems to be causing trouble, since I have to specify a longitude value,
>when I dont want to.
>
>       Here is the beef of what I am trying now.
>
>$GEMEXE/gdcross
>       CXSTNS  = -80.;150.>80.;150.
>       GFUNC   = xav(uwnd)
>
>
>       This will produce a nice plot, but if I chose a different value
>for CXSTNS, then the plot changes, which makes me believe that xav is
>indeed not working.
>
>       Any ideas?
>
>Thanks much,
>       Daryl
>                                                    __   ,,,,
>                                                   /  \_|$$$$|__,
>                                                   |     ==========}
>,,,,,, Daryl Herzmann  [ SR - MTEOR ]   ,,,,,,,,   +--+ JOHN    |_
>!!!!!! address@hidden              !!!!!!!! ___  |  DEERE ,_/
>$$$$$$ www.public.iastate.edu/~akrherz  $$$$$$$$/__|==-__-----_|
>|||||| ICQ: 25560887 AOL: "Daryl Herz"  ||||||||_______{}_____o_____
>
>
>