R: Meaning of descriptor file (*.ctl) variable names

[Diego Morelli]

Hello Wesley,

Can I say that the rule is:

If, about a certain variable relative to an isobaric level, it's available
only one level, then the variable get the suffix <level>+<mb>, otherwise it
get the suffix "prs" ??

In the attachment there is a file in which there is 2 variables available on
2 levels, and they are declared of the kind "prs". Here bottom is its ctl
file.

dset /home/cyprus/grads/compiled_env/grads-2.0.a7.1/bin/cyprus.b
index /home/cyprus/grads/compiled_env/grads-2.0.a7.1/bin/cyprus.b.idx
undef 9.999E+20
title /home/cyprus/grads/compiled_env/grads-2.0.a7.1/bin/cyprus.b
*  produced by grib2ctl v0.9.12.5p45
dtype grib 11
options yrev
ydef 37 linear -90.000000 2.5
xdef 37 linear 90.000000 2.500000
tdef 1 linear 00Z28apr2005 1mo
*  z has 2 levels, for prs
zdef 2 levels
850 500
vars 4
HGT500mb  0 7,100,500 ** 500 mb Geopotential height [gpm]
PRMSLsfc  0 2,1,0  ** surface Pressure reduced to MSL [Pa]
UGRDprs 2 33,100,0 ** (profile) u wind [m/s]
VGRDprs 2 34,100,0 ** (profile) v wind [m/s]
ENDVARS

-----Messaggio originale-----
Da: GRADSUSR at LIST.CINECA.IT [mailto:GRADSUSR at LIST.CINECA.IT] Per conto di
Wesley Ebisuzaki
Inviato: giovedì 12 novembre 2009 16.02
A: GRADSUSR at LIST.CINECA.IT
Oggetto: Re: Meaning of descriptor file (*.ctl) variable names

Diego,

Sometimes a variable may be available as a vertical profile. Sometimes a
variable may only be available on
one or two levels. When a variable is available as a vertical profile on
pressure surfaces, the suffix "prs" is
used. If the variable is not available on a vertical profile, the suffix
is the level descriptor.

Wesley Ebisuzaki


Diego Morelli wrote:
>
> When I use grib2ctl (v0.9.12.5p45) it issues a ctl file with some
> variables having the suffix “mb”. These variables are relative to an
> isobaric level type (value 100 in the PDS grib section, octet number
> 10), with a value expressed in hPa.
>
> I see that the variables with suffix prs are relative also to an
> isobaric level type.
>
> My questions is to know what is the difference between the variable
> with suffix mb and those with suffix prs.
>
> Here there is an example of a descriptor file:
>
>
----------------------------------------------------------------------------
----------------------------------------------
>
>
> dset ^LFPW00190127.20090718144212_P4320PT76BE_BPMG12.86093.b
>
> index ^LFPW00190127.20090718144212_P4320PT76BE_BPMG12.86093.b.idx
>
> undef 9.999E+20
>
> title LFPW00190127.20090718144212_P4320PT76BE_BPMG12.86093.b
>
> * produced by grib2ctl v0.9.12.5p45
>
> dtype grib 255
>
> options yrev
>
> ydef 66 linear 10.000000 1
>
> xdef 126 linear -60.000000 1.000000
>
> tdef 1 linear 12Z18jul2009 1mo
>
> * z has 6 levels, for prs
>
> zdef 6 levels
>
> 925 850 700 500 400 300
>
> vars 2
>
> * GPprs * 6 6,*100*,0 ** (profile) Geopotential [m^2/s^2]
>
> * VGRD925mb * 0 34,*100*,925 ** 925 mb v wind [m/s]
>
> ENDVARS
>
>
----------------------------------------------------------------------------
----------------------------------------------
>
>
> Regards,
>
> Diego
>
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