20060627: GDDIAG problem in GEMPAK

  • To: "Melick, Christopher ""James (UMC-Student)" <cjmzr5@xxxxxxxxxx>
  • Subject: 20060627: GDDIAG problem in GEMPAK
  • From: Steve Chiswell <chiz@xxxxxxxxxxxxxxxx>
  • Date: 27 Jun 2006 14:21:16 -0600
Chris,

Your problem in precision of the stored diagnostic is due to your GPACK
setting in GDDIAG.

The GPACK parameter will use GRIB/16 if left blank. Since you identified
the problem as a large range of data values, you likely need to increase
the number of packing bits being used, or set GPACK=NONE.

Steve Chiswell
Unidata User Support


On Tue, 2006-06-27 at 13:59, Melick, Christopher James (UMC-Student)
wrote:
Hello,
I am having problems with the output generated within GDDIAG when I am declaring a parameter in GRDNAM that is the quotient of two parameters, the one in the denominator encompassing a large range in scales [in this instance, the squared difference of the vertical change in geostrophic wind]. Several grid points will have identical values if I use the newly generated grid file which should not occur. However, a completely different and more accurate result will occur if I manually type in the quotient of the two parameters myself in GFUNC. What causes this and is there a means to fix it?? I hope I have explained my dilemma clearly and completely enough to follow. There are no GEMPAK errors in the logfiles and I have tried creating a separate script just for this particular term with no success. Thank you very much,
Chris Melick
___________________________________________________________
Christopher J. Melick
Ph.D. Student, Atmospheric Science
Department of Soil, Env, and Atmos Sciences
University of Missouri-Columbia
302 ABNR Building
Columbia, MO 65211

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