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20040604: NOMADS site/IDV (re. Don Murray)

>From: NATHAN LOUIS UHLENBROCK <address@hidden>
>Organization: SSEC
>Keywords: 200406041834.i54IY0tK028702 IDV GDS

Hi Nate-

>Tom W. and I tried to get model data from the NOMADS website:(<http://nomads.n
> cdc.noaa.gov/data-access.html#weather_datasets>.
>When you click on "gds" for one of the models, then on the day, then on the ru
> n you want, and finally on "info" for that run, you get a DODS url for the da
> ta.  We tried to load the url into IDV and the only data that we could get wa
> s the 2D data (and I REALLY need the 3D!).  Also, the parameters available se
> emed to have extrenous script in them...sort of weird.  Anyways, I thought th
> is was an excellent source for archived model data, so maybe you could take a
>  look and see what you get.  

I had thought of suggesting this to you in my previous note, but I
wasn't sure how well the IDV would handle these data.  Also, there
was a time when the data didn't have any units associated with it so
that made it even more incompatible.

>Here is an example:  When this url is entered into IDV, I only get 2D data.  H
> owever, by looking at the dds, it is obvious that it contains much more than 
> what I am getting.  Here is the url I last used:
>
>http://nomads.ncdc.noaa.gov:9090/dods/NCDC_NOAAPort_RUC/200406/20040604/ruc_21
> 1_20040604_1700_fff
>
>Hope this all makes some sort of sense!  Thanks!

The problem is that the vertical level unit is given as "mb" which is
technically not a standard definition for millibar. It should be mbar or
hPa. The files say they are COARDS compliant, but that vertical unit is
Unlike CF which requires it, COARDS only strongly recommends adhering
to udunits standards for unit specifications. So, I guess technically,
using "mb" is okay, but hard to deal with.

This is all a function of the GRADS/DODS server.  We could probably 
kludge something on our end, but they should really fix it on
their server.  I've cc'd the developer of the netCDF/DODS interface
for his comments.  That is where the "mb" is causing problems.

I'll be out until next week, but will put it on my list of things
to do.

Don Murray
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