[Met_help] [rt.rap.ucar.edu #42668] History for queries regarding MODE component of METv3.0 software
RAL HelpDesk {for John Halley Gotway}
met_help at ucar.edu
Mon Dec 13 09:04:16 MST 2010
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Initial Request
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Hi,
I am a Meteorologist at the India Meteorological Department, New Delhi.
I wish to use the MET software (more specifically the MODE component) to validate the output of the Nowcasting softwares that were operationally run during the Commonwealth Games, 2010 at Delhi. I have the following queries, and will be grateful if you can help in this regard.
1. My data is reflectivity values in a 1 km x 1 km domain over a part of the Indian region. Projection is lat-lon. i checked the link http://www.nco.ncep.noaa.gov/pmb/docs/on388/tableb.html
But am unable to decide which of the grids to use. can you please help.
2. I need an example netcdf file of a similar quantity in lat-lon projection that i can input into the MODE software. the examples files provided with the installation package are all in lambert conformal projection. I need a file in whose model i will convert my files, to input into the MODE package.
3. Any other corrections i need to make?
thank you and regards
Dr. Soma Sen Roy
Meteorologist
India Meteorological Department
Delhi 110034
India
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Complete Ticket History
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Subject: queries regarding MODE component of METv3.0 software
From: John Halley Gotway
Time: Fri Dec 10 09:59:19 2010
Dr. Soma Sen Roy,
Based on your first question, it sounds like there's some
misunderstanding about what type of gridded data the MET tools can
support. You are not limited to just the grids defined in that GRIB
documentation
(http://www.nco.ncep.noaa.gov/pmb/docs/on388/tableb.html). Instead,
MET parses the grid definition information from the input GRIB or
NetCDF files and instantiates the grid those
parameters define. So really, MET can handle any regular grid defined
on a polar stereographic, lat/lon, lambert conformal, or mercator
projection.
The copygb tool is useful for regridding data in GRIB format.
However, it sounds like you're dealing with NetCDF data and would like
to set it up for the MET tools to read. In order to do that, I'd
suggest making it look like the output of the MET/PCP-Combine tool.
That way, MODE should be able to read it.
Using the commands listed below, I ran some sample data through copygb
to regrid it to a lat/lon grid, and then I ran it through pcp_combine
to get it into NetCDF format:
cd METv3.0/data/sample_obs/ST2ml
copygb -xg"255 0 20 20 30000 -110000 128 50000 -90000 1000 1000 64"
ST2ml2005080800.Grb_G212 ST2ml2005080800.Grb_latlon
../../../bin/pcp_combine -add ST2ml2005080800.Grb_latlon 01
ST2ml2005080800.Grb_latlon.nc
The resulting NetCDF file is attached. And here's the header for that
file:
netcdf ST2ml2005080800.Grb_latlon {
dimensions:
lat = 20 ;
lon = 20 ;
variables:
float lat(lat, lon) ;
lat:long_name = "latitude" ;
lat:units = "degrees_north" ;
lat:standard_name = "latitude" ;
float lon(lat, lon) ;
lon:long_name = "longitude" ;
lon:units = "degrees_east" ;
lon:standard_name = "longitude" ;
float APCP_01(lat, lon) ;
APCP_01:name = "APCP" ;
APCP_01:long_name = "Total precipitation" ;
APCP_01:level = "A1" ;
APCP_01:units = "kg/m^2" ;
APCP_01:grib_code = 61 ;
APCP_01:_FillValue = -9999.f ;
APCP_01:init_time = "20050807_230000" ;
APCP_01:init_time_ut = 1123455600 ;
APCP_01:valid_time = "20050808_000000" ;
APCP_01:valid_time_ut = 1123459200 ;
APCP_01:accum_time = "010000" ;
APCP_01:accum_time_sec = 3600 ;
// global attributes:
:FileOrigins = "File ST2ml2005080800.Grb_latlon.nc
generated 20101210_165425 UTC on host rambler by the MET pcp_combine
tool" ;
:MET_version = "V3.0" ;
:MET_tool = "pcp_combine" ;
:RunCommand = "Addition: 1 files." ;
:Projection = "LatLon" ;
:lat_ll = "30.000000 degrees_north" ;
:lon_ll = "-110.000000 degrees_east" ;
:delta_lat = "1.000000 degrees" ;
:delta_lon = "1.000000 degrees" ;
:Nlat = "20 grid_points" ;
:Nlon = "20 grid_points" ;
}
Specifically, you're NetCDF file should contain the same type of
global attributes this one does:
MET_version, Projection, lat_ll, lon_ll, delta_lat, delta_lon,
Nlat, and Nlon.
These define the grid on which your data resides.
Next, your NetCDF file should use dimensions named lat and lon. You
do NOT need to include the lat(lat,lon) and lon(lat,lon) variables.
But each you variables containing the reflectivity data should
be sized using the (lat, lon) dimensions. Also, they should include
the variable attributes listed above. The attributes ending in "_ut"
are for unix time - the number of seconds since Jan 1, 1970.
Hope this helps. Let me know if you get stuck.
Thanks,
John Halley Gotway
On 12/10/2010 04:42 AM, RAL HelpDesk {for soma senroy} wrote:
>
> Fri Dec 10 04:42:21 2010: Request 42668 was acted upon.
> Transaction: Ticket created by somasenroy at yahoo.com
> Queue: met_help
> Subject: queries regarding MODE component of METv3.0 software
> Owner: Nobody
> Requestors: somasenroy at yahoo.com
> Status: new
> Ticket <URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=42668 >
>
>
> Hi,
> I am a Meteorologist at the India Meteorological Department, New
Delhi.
> I wish to use the MET software (more specifically the MODE
component) to validate the output of the Nowcasting softwares that
were operationally run during the Commonwealth Games, 2010 at Delhi. I
have the following queries, and will be grateful if you can help in
this regard.
>
> 1. My data is reflectivity values in a 1 km x 1 km domain over a
part of the Indian region. Projection is lat-lon. i checked the link
http://www.nco.ncep.noaa.gov/pmb/docs/on388/tableb.html
> But am unable to decide which of the grids to use. can you please
help.
>
> 2. I need an example netcdf file of a similar quantity in lat-lon
projection that i can input into the MODE software. the examples files
provided with the installation package are all in lambert conformal
projection. I need a file in whose model i will convert my files, to
input into the MODE package.
> 3. Any other corrections i need to make?
>
> thank you and regards
>
> Dr. Soma Sen Roy
> Meteorologist
> India Meteorological Department
> Delhi 110034
> India
>
>
------------------------------------------------
Subject: Re: [rt.rap.ucar.edu #42668] queries regarding MODE component of METv3.0 software
From: soma senroy
Time: Mon Dec 13 01:43:23 2010
Dear Dr. Gotway,
Thank you for the prompt reply. I will get back to you I have any
other queries.
regards
soma sen roy
--- On Fri, 10/12/10, RAL HelpDesk {for John Halley Gotway}
<met_help at ucar.edu> wrote:
> From: RAL HelpDesk {for John Halley Gotway} <met_help at ucar.edu>
> Subject: Re: [rt.rap.ucar.edu #42668] queries regarding MODE
component of METv3.0 software
> To: somasenroy at yahoo.com
> Date: Friday, 10 December, 2010, 11:59 AM
> Dr. Soma Sen Roy,
>
> Based on your first question, it sounds like there's some
> misunderstanding about what type of gridded data the MET
> tools can support. You are not limited to just the
> grids defined in that GRIB
> documentation
(http://www.nco.ncep.noaa.gov/pmb/docs/on388/tableb.html).
> Instead,
MET parses the grid definition information from the
> input GRIB or NetCDF files and instantiates the grid those
> parameters define. So really, MET can handle any
> regular grid defined on a polar stereographic, lat/lon,
> lambert conformal, or mercator projection.
>
> The copygb tool is useful for regridding data in GRIB
> format. However, it sounds like you're dealing with
> NetCDF data and would like to set it up for the MET tools to
> read. In order to do that, I'd
> suggest making it look like the output of the
> MET/PCP-Combine tool. That way, MODE should be able to
> read it.
>
> Using the commands listed below, I ran some sample data
> through copygb to regrid it to a lat/lon grid, and then I
> ran it through pcp_combine to get it into NetCDF format:
>
> cd METv3.0/data/sample_obs/ST2ml
> copygb -xg"255 0 20 20 30000 -110000 128 50000 -90000 1000
> 1000 64" ST2ml2005080800.Grb_G212
> ST2ml2005080800.Grb_latlon
> ../../../bin/pcp_combine -add ST2ml2005080800.Grb_latlon 01
> ST2ml2005080800.Grb_latlon.nc
>
> The resulting NetCDF file is attached. And here's the
> header for that file:
>
> netcdf ST2ml2005080800.Grb_latlon {
> dimensions:
> lat = 20 ;
> lon = 20 ;
> variables:
> float lat(lat, lon) ;
>
> lat:long_name = "latitude" ;
>
> lat:units = "degrees_north" ;
>
> lat:standard_name = "latitude" ;
> float lon(lat, lon) ;
>
> lon:long_name = "longitude" ;
>
> lon:units = "degrees_east" ;
>
> lon:standard_name = "longitude" ;
> float APCP_01(lat, lon) ;
>
> APCP_01:name = "APCP" ;
>
> APCP_01:long_name = "Total precipitation" ;
>
> APCP_01:level = "A1" ;
>
> APCP_01:units = "kg/m^2" ;
>
> APCP_01:grib_code = 61 ;
>
> APCP_01:_FillValue = -9999.f ;
>
> APCP_01:init_time = "20050807_230000" ;
>
> APCP_01:init_time_ut = 1123455600 ;
>
> APCP_01:valid_time = "20050808_000000" ;
>
> APCP_01:valid_time_ut = 1123459200 ;
>
> APCP_01:accum_time = "010000" ;
>
> APCP_01:accum_time_sec = 3600 ;
>
> // global attributes:
>
> :FileOrigins = "File ST2ml2005080800.Grb_latlon.nc
generated
> 20101210_165425 UTC on host rambler by the MET pcp_combine
> tool" ;
>
> :MET_version = "V3.0" ;
>
> :MET_tool = "pcp_combine" ;
>
> :RunCommand = "Addition: 1 files." ;
>
> :Projection = "LatLon" ;
>
> :lat_ll = "30.000000 degrees_north" ;
>
> :lon_ll = "-110.000000 degrees_east" ;
>
> :delta_lat = "1.000000 degrees" ;
>
> :delta_lon = "1.000000 degrees" ;
>
> :Nlat = "20 grid_points" ;
>
> :Nlon = "20 grid_points" ;
> }
>
>
> Specifically, you're NetCDF file should contain the same
> type of global attributes this one does:
> MET_version, Projection, lat_ll, lon_ll,
> delta_lat, delta_lon, Nlat, and Nlon.
> These define the grid on which your data resides.
>
> Next, your NetCDF file should use dimensions named lat and
> lon. You do NOT need to include the lat(lat,lon) and
> lon(lat,lon) variables. But each you variables
> containing the reflectivity data should
> be sized using the (lat, lon) dimensions. Also, they
> should include the variable attributes listed above.
> The
attributes ending in "_ut" are for unix time - the
> number of seconds since Jan 1, 1970.
>
> Hope this helps. Let me know if you get stuck.
>
> Thanks,
> John Halley Gotway
>
>
>
>
> On 12/10/2010 04:42 AM, RAL HelpDesk {for soma senroy}
> wrote:
> >
> > Fri Dec 10 04:42:21 2010: Request 42668 was acted
> upon.
> > Transaction: Ticket created by somasenroy at yahoo.com
> > Queue: met_help
> > Subject: queries regarding MODE
> component of METv3.0 software
> > Owner: Nobody
> > Requestors: somasenroy at yahoo.com
> > Status: new
> > Ticket <URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=42668
> >
> >
> >
> > Hi,
> > I am a Meteorologist at the India Meteorological
> Department, New Delhi.
> > I wish to use the MET software (more specifically the
> MODE component) to validate the output of the Nowcasting
> softwares that were operationally run during the
> Commonwealth Games, 2010 at Delhi. I have the following
> queries, and will be grateful if you can help in this
> regard.
> >
> > 1. My data is reflectivity values in a 1 km x 1 km
> domain over a part of the Indian region. Projection is
> lat-lon. i checked the link
http://www.nco.ncep.noaa.gov/pmb/docs/on388/tableb.html
> > But am unable to decide which of the grids to use. can
> you please help.
> >
> > 2. I need an example netcdf file of a similar quantity
> in lat-lon projection that i can input into the MODE
> software. the examples files provided with the installation
> package are all in lambert conformal projection. I need a
> file in whose model i will convert my files, to input into
> the MODE package.
> > 3. Any other corrections i need to make?
> >
> > thank you and regards
> >
> > Dr. Soma Sen Roy
> > Meteorologist
> > India Meteorological Department
> > Delhi 110034
> > India
> >
> >
>
>
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