20020131: OABSND analysis in GEMPAK

Patrick,

OABSND will interpolate the levels of each sounding to your list of 
levels input.

See: $GEMPAK/source/gemlib/pc/pccmvr.f, pccmdt.f

The interpolation is possible if your coord is PRES, HGHT, or THTA.

Since you are on pressure levels, the interpolation will be 
done with respect to log pressure: pcintp.f

Steve Chiswell
Unidata User Support


>From: "Market, Patrick S." <address@hidden>
>Organization: UCAR/Unidata
>Keywords: 200201311916.g0VJGWx27073

>Hello.
>
>I am writing to inquire how GEMPAK does an objective analysis of sounding file
> s at non-mandatory levels.
>
>Our current work requires us to maintain the best possible vertical resolution
>  in our gridded files from the RAOB data.  For the first time, I set
>
>LEVELS=0;1000;950;900;850;800;750;700...   etc.
>
>and saw that even at non-mandatory levels (e.g., 750 mb) the full suite of sta
> tions was accounted for.  I did not know this was possible.  For years I had 
> labored under the impression that doing so would yield incomplete/invalid fie
> lds at non-mandatory levels.
>
>Have I been wrong?  If so, how does GEMPAK achieve data representation on leve
> ls like 750 mb?  Does it interpolate for each station to the unobserved level
>  and then Barnes that result?  If not, then what am I getting at levels like 
> 750?  And do I need to write my own interpolation routine?  I'd like to know 
> before I OABSND the next 123 cases...
>
>Thanks.
>
>Pat
>
>Dr. Patrick S. Market
>University of Missouri-Columbia
>Dept. of Atmospheric Science
>203 Gentry Hall
>Columbia, MO  65211
>(573)882-1496   Web: http://web.missouri.edu/~marketp
>