[Met_help] [rt.rap.ucar.edu #80850] History for Additional question on task number 80844

[John Halley Gotway via RT]

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  Initial Request
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John, when I create a netCDF file of a 2D data array of model data, do I need to include latitude and longitude variables.  I noticed that was what your code was doing when converting WWMCA to netCDF.  Also, I fixed my code to place a string version of the valid_time_ut field and the init_time_ut field in the netCDF variable.  However I noticed that these time fields are attributes of the main variable instead of global attributes as I included them.   Is there a template of how a netCDF file should be defined for MET to read it correctly.  I am using python netCDF4 library to create these files using a "netCDF3_CLASSIC" option.

Thanks
Bob



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  Complete Ticket History
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Subject: Additional question on task number 80844
From: John Halley Gotway
Time: Tue Jun 13 16:15:08 2017

Bob,

I understand that we don't have good documentation defining the
internal
NetCDF format used by the MET tools.  MET supports a few different
variants
of NetCDF.

(1) The internal NetCDF format that you're using looks like the output
of
the pcp_combine tool (and really any other gridded NetCDF file that
MET
writes).  There actually is no need to include the lat/lon variables
since
MET defines the grid information using the global attributes.

(2) The NetCDF output of the wrf_interp utility is a very specific
format.

(3) The Climate Forecast (CF) convention is a much more general and
broadly
used standard.

Ultimately, I'd prefer for the MET tools to move from our very
restrictive
format of (1) and start using the CF-convention (3) instead.

But that hasn't risen to the top of the priority list yet.

I have many old open tickets from you.  Please let me know once we get
to a
good stop, and I'll resolve all the old ones.  And then we can open
new
ones as needed.

Thanks,
John

On Tue, Jun 13, 2017 at 1:41 PM, robert.craig.2 at us.af.mil via RT <
met_help at ucar.edu> wrote:

>
> Tue Jun 13 13:41:05 2017: Request 80850 was acted upon.
> Transaction: Ticket created by robert.craig.2 at us.af.mil
>        Queue: met_help
>      Subject: Additional question on task number 80844
>        Owner: Nobody
>   Requestors: robert.craig.2 at us.af.mil
>       Status: new
>  Ticket <URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=80850 >
>
>
> John, when I create a netCDF file of a 2D data array of model data,
do I
> need to include latitude and longitude variables.  I noticed that
was what
> your code was doing when converting WWMCA to netCDF.  Also, I fixed
my code
> to place a string version of the valid_time_ut field and the
init_time_ut
> field in the netCDF variable.  However I noticed that these time
fields are
> attributes of the main variable instead of global attributes as I
included
> them.   Is there a template of how a netCDF file should be defined
for MET
> to read it correctly.  I am using python netCDF4 library to create
these
> files using a "netCDF3_CLASSIC" option.
>
> Thanks
> Bob
>
>
>

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