[idvusers] HOW TO : Plot views across the prime meridian using IDV

• To: <idvusers@xxxxxxxxxxxxxxxx>
• Subject: [idvusers] HOW TO : Plot views across the prime meridian using IDV
• From: "webmaster-IWC" <webmaster@xxxxxxxxxxxxxxxxxxxxxxxxxx>
• Date: Tue, 8 Jan 2008 15:01:50 -0000

Hi all,
 
OK I have managed to get around this problem with plotting across the
prime meridian - and it works, which did surprise me!
So I thought I would share how this can be done.
 
Data set
GFS global model 1x1 deg from NCEP
 
Software required
IDV (unidata | display)
Cnvgrib (NCO | convert grib 2 to grib 1)
Convsh + Subset.tcl (BADC | create regional subsets into NetCDF)
 
1. First download your data. You need to download the whole grid as
cnvgrib will not work with partial downloading of grib files
2. Use Cnvgrib to convert grib 2 files into grib 1 (Example cnvgrib -g21
gfs.t00z.pgrbf09.grib2 subset.grb)
3. Create a regional subset from the new grib 1 file data set (Example
convsh subset.tcl -i subset.grb -o subset.nc -xs -60 -xe 60 -xi 1 -ys 0
-ye 90 -yi 1)
 
The new subset file is now in NetCDF format with the starting grid lon @
-60, this fixes the problem that IDV has plotting across the meridian.
 
FOR XP USERS ONLY.
 
I have complied copy of Cnvgrib.exe if any users require this.
 
Other programs and documents needed can be found below:
 
BADC
HYPERLINK
"http://badc.nerc.ac.uk/help/software/xconv/#utilites"http://badc.nerc.a
c.uk/help/software/xconv/#utilites
HYPERLINK
"http://badc.nerc.ac.uk/help/software/xconv/subset.html"http://badc.nerc
.ac.uk/help/software/xconv/subset.html
 
NCO
HYPERLINK
"http://www.nco.ncep.noaa.gov/pmb/codes/GRIB2/"http://www.nco.ncep.noaa.
gov/pmb/codes/GRIB2/
 
Good luck and have fun
 
Ian
 
 
 
 
 
 
 

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  • Re: [idvusers] HOW TO : Plot views across the prime meridian using IDV
    • From: Don Murray