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20010411: garp and dateline

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  • Subject: 20010411: garp and dateline
  • Date: Wed, 11 Apr 2001 13:48:54 -0600
>From: <address@hidden>
>Organization: UCAR/Unidata
>Keywords: 200104111823.f3BINHL14797

>Steve,
>  Do you know of any issue with GARP and GEMPAK and plotting grids that
>cross the international dateline? When I plot my grid it seems to draw
>extra lines as if there is a gradient there.  I've tested this from the
>RAMS model output. I set up the lat/lon points from my model output to a
>GEMPAK grid and then viewed it with GARP and gdcntr. Both produced a bunch
>of lines along the dateline. I've matched the grid projections so that
>they're the same between the RAMS output and gempak; so the projections
>are equal. Any ideas?
>
>Steve Saleeby
>Colorado State University
>
>
>-- 
>*************************************************************
>"The eternal God is our refuge, and underneath are the
>everlasting arms."    -Deuteronomy 31:27-
>
>Stephen Millican Saleeby  (address@hidden)
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>


Steve,

You didn't mention if you were using the sm5s() or sm9s() functions.
GEMPAK does handle the grid wrap at whatever point that is (for the AVN 
thinned grids the wrap is at 30W). However, if you are using a smoothing
function, you will create a discontinuity. Since some of the Garp
fdf's use sm5s() (such a sm5s(hght)), you might check that.

Steve Chiswell