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20040217: Plotting THTV vs. Height

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  • Subject: 20040217: Plotting THTV vs. Height
  • Date: Tue, 17 Feb 2004 11:19:46 -0700
Patrick,

Try running GDDIAG firat to compute the THTV grids
on your pressure surfaces and write these into your data file,
then do the GDVINT interpolation of the pressure level grids 
to the ZAGL coordinate so that the THTV grids are found on 
that coordinate- rather than having to try to compute them
in the ZAGL coordinate. This worked for me.

Steve Chiswell



>From: "Patrick O'Reilly" <address@hidden>
>Organization: UCAR/Unidata
>Keywords: 200402171737.i1HHb6rV010098

>I was successful in creating THTV profiles vs. pressure from model data.
>What I really want though is plots of THTV vs. height above ground (ZAGL).
>So, I interpolated my grids from PRES to ZAGL.  Then I tried to run GDPROF
>with settings below, plotting THTV vs. ZAGL, but get nonsense (-INF for
>data, which I'm guessing is -infinity).  Due to the calculation of THTV, is
>it necessary to plot this vs. pressure?  In my ZAGL grids, I do have PRES,
>TMPK and SPFH as forecast fields, so I thought I had everything I needed to
>calculate THTV.  What I have done and what I get:
>
>GEMPAK-GDPROF>l
> GPOINT   = alo
> GDATTIM  = 040217/0600f000
> GVCORD   = zagl
> GFUNC    = thtv
> GVECT    =
> GDFILE   = 04021706_wseta_zagl.gem
> LINE     = 3
> MARKER   = 0
> BORDER   = 1
> PTYPE    = lin
> SCALE    = 0
> XAXIS    = 250/400/10
> YAXIS    = 0/2000/100
> WIND     =
> REFVEC   =
> WINPOS   = 1
> FILTER   = no
> TITLE    = 1
> PANEL    = 0
> CLEAR    = YES
> TEXT     = 1
> DEVICE   = XW
> OUTPUT   = t
> THTALN   = 0
> THTELN   = 0
> MIXRLN   = 0
> GEMPAK-GDPROF>r
> GDPROF PARAMETERS
>
> Grid file:                 04021706_wseta_zagl.gem
> Grid time:                 040217/0600F000
> Grid function:             thtv
> Grid vector function:
> X,Y grid point:             58.42   45.90
> Lat/lon:                    42.55  -92.40
> Number of levels:           41
> Data range:                  -inf    -inf
> Scaling factor:             10** 0
> Wind display:
>
>Enter <cr> to accept parameters or type EXIT:
>
>
>                                    PROFILE
>
>
>       040217/0600V000  THTV   ALO
>
>
>       LATITUDE, LONGITUDE = (  42.55,  -92.40 )
>
>
>                  ZAGL                  THTV
>                   0.00                 -INF
>                  50.00                 -INF
>                 100.00                 -INF
>                 150.00                 -INF
>                 200.00                 -INF
>                 250.00                 -INF
>                 300.00                 -INF
>                 350.00                 -INF
>                 400.00                 -INF
>                 450.00                 -INF
>                 500.00                 -INF
>                 550.00                 -INF
>                 600.00                 -INF
>                 650.00                 -INF
>                 700.00                 -INF
>                 750.00                 -INF
>                 800.00                 -INF
>                 850.00                 -INF
>                 900.00                 -INF
>                 950.00                 -INF
>                1000.00                 -INF
>                1050.00                 -INF
>                1100.00                 -INF
>                1150.00                 -INF
>                1200.00                 -INF
>                1250.00                 -INF
>                1300.00                 -INF
>                1350.00                 -INF
>                1400.00                 -INF
>                1450.00                 -INF
>                1500.00                 -INF
>                1550.00                 -INF
>                1600.00                 -INF
>                1650.00                 -INF
>                1700.00                 -INF
>                1750.00                 -INF
>                1800.00                 -INF
>                1850.00                 -INF
>                1900.00                 -INF
>                1950.00                 -INF
>                2000.00                 -INF
> Parameters requested: GPOINT,GDATTIM,GVCORD,GFUNC,GVECT,GDFILE,LINE,MARKER,
> BORDER,PTYPE,SCALE,XAXIS,YAXIS,WIND,REFVEC,WINPOS,FILTER,TITLE,PANEL,CLEAR,
> TEXT,DEVICE,OUTPUT,THTALN,THTELN,MIXRLN.
> GEMPAK-GDPROF>
>
>Thanks for your assistance.
>
>Patrick
>_________________________________________
>Patrick O'Reilly
>Meteorological Decision Support Scientist
>The STORM Project at UNI
>address@hidden    319-273-3789
>http://www.uni.edu/storm
>
>"No trees were killed in the making of this e-mail...however,
> a large number of electrons were horribly inconvenienced."
>
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