20010104: LINUX GARP Not "Seeing" Isentropic Surfaces

Bob,

I believe that this is a known feature of Garp's design rather than a bug
per se....I'm assuming you can talk to Steve Drake and/or Jim Cowie
(now at RAP) as to whether this is the case.

Garp speeds things up by not opening every grid file and
searching through for the levels/coordinates. Rather, it assumes that the
levels/coordinates in the first are repesentative of what will be in that models
files. If the use is creating additional levels/coordinates to some
files, then that really isn't representative of the output.
It actually slows things down a lot (especially for hourly ruc files)
to open and read every file that matches the model key.

You have a choice. If the user is creating certain levels/fields,
do it to a different file, not the NCEP fields. That way, there is
no confusion later about where the data came from....eg, its not
from the ETA run, but from a gdvint interpolation. Add the
other file name model keys to the Garp_defaults.

Let me know if I'm not interpreting your question correctly.

Steve




On Fri, 4 Jan 2002, Bob Rozumalski wrote:

>
>
> Steve,
>
> The following message describes a bug that was found in Garp
> and verified here in under both HPUX and LINUX.  I was just
> wondering if you were aware of the problem.  If you want access
> to the gempak files used for testing let me know.
>
> Bob
>
>
>
> ------------- Begin Forwarded Message -------------
>
> >From address@hidden Fri Jan  4 12:27:37 2002
> Date: Fri, 04 Jan 2002 13:27:27 -0600
> From: "Bernard N. Meisner" <address@hidden>
> X-Accept-Language: en
> MIME-Version: 1.0
> To: Bob Rozumalski <address@hidden>
> CC: Mike Bender <address@hidden>
> Subject: Re: LINUX GARP Not "Seeing" Isentropic Surfaces
> Content-Transfer-Encoding: 7bit
>
> Hi Bob!
>
> Your suggestion of removing all GEMPAK files except the one with the
> isentropic surfaces helped me further diagnose the problem.  I've placed
> two additional files in the for_bob directory on your server.  They
> are:  02010300_eta.gem and 02010400_eta.gem  Those files are from the
> runs immediately before and after the one with the isentropic surfaces
> added (02010312_eta.gem).  However, there are no isentropic fields in
> these two files.
>
> Now, try this experiment:
>
>     1)  Place only the 02010312_eta.gem file in the data directory.
> GARP will "see" and display the isentropic data fields without problem.
>
>     2)  Add the 02010400_eta.gem file to the data directory.  This file
> is chronologically after the one with the isentropic surfaces, but does
> not contain any isentropic data.  Restart GARP and note that when you
> select times from the added file (0000 UTC 4 Jan) and select
> "Isentropic" from the pull-down menu the "Level1" icon will be active
> and show the various levels stored in the earlier (1200 UTC 3 Jan) data
> file.  Of course, GARP will only produce blank maps from the 0000 UTC 4
> Jan file since there aren't any isentropic fields to display.
>
>     3)  Now add the 02010300_eta.gem file to the data directory.  This
> file is chronologically before the one with the isentropic surfaces, and
> does not contain any isentropic data.  Restart GARP and note that when
> you select times from any of the three files now in the directory and
> select "Isentropic" from the pull-down menu, the Level1 icon will not be
> active and you cannot plot any isentropic fields from any of the data
> files.
>
> Apparently GARP looks at the first file in the data directory which
> matches the specification in the Garp.defaults file for that model
> choice to determine what fields are available for plotting.  If there
> are no isentropic fields in the "first" file, then GARP won't let you
> plot any from the other data files, even if they contain isentropic
> data.  If there are isentropic fields in the "first" file, then GARP
> will let you try to plot from any of the files, even if they don't
> contain isentropic data.  Of course, only blank maps are plotted for
> those files.
>
> Cheers!
>
> Bernard
>
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>