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19990317: HGHT vs HAGL coordinates

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  • Subject: 19990317: HGHT vs HAGL coordinates
  • Date: Wed, 17 Mar 1999 13:28:39 -0700
Ron,

DFW's station elevation is 182 m.
It sounds like you are confusing vertical coordinates of HGHT and HAGL.

Your heights you list below are relative to the ground level (HAGL),
however the HGHT coordinate is absolute. Since the ground elevation at DFW
is 182m, specifying gvcord=HGHT and glevel = 5 would be 177m below ground
and not displayed. If you are interpolating your data relative to
the DFW ground postion, you will have to add the station elevation to
correctly interpret the HGHT coordinate.

Also, in the future, be sure to send all questions to
address@hidden so that I can find them and enter them
into our tracking system.

Steve Chiswell
Unidata User Support


On Thu, 31 Dec 1998, Ronald Weglarz wrote:

> Hi, Steve --
>       Hope that you had a nice Xmas, and best wishes for the New Year. I have
> a question regarding GDPROF (I am working with version 5.2.1 of GEMPAK).
> Although I have used GDVINT to interpolate MASS model data from PRES vert.
> coord. to HGHT coord., and have data at the sfc, 5m, 25m, 45m, 65m, etc. up
> to 305 m (i.e. I am very close to the sfc within the PBL), and can plot up
> (using e.g. GDCNTR) a horizontal cross section of geostrophic, ageostrophic,
> or total winds at any of these vertical levels, when I attempt to run GDPROF
> to plot up vertical profiles of geostrophic, ageostrophic, or total winds
> *at a particular location within the grid domain* (in my case DFW or Dallas/
> Fort Worth), GDPROF will not return any values below a certain level, ~200m
> *even though GDCNTR plots indicate that I have physically realistic values
> at all levels below down to the sfc.  Is ther any quick fix/way around this
> problem, as I particularly need to generate vertical profiles from the sfc
> up to ~300m in order to compare with observational data.  thanks for your
> time and help!  regards, -ron
> 
> =============================
> Dr. Ronald P. Weglarz
> Visit. Asst. Prof.
> Dept. MEAS
> Campus Box 8208
> NC State University
> Raleigh, NC 27695-8208
> [tel] 919-515-1442
> [fax] 919-515-1683
> [email] address@hidden (OR address@hidden)
>