Thanks for the reply Robb. I misunderstood how the query worked. I thought
I could specify the variable and a height and a file would be created. I am
new to this stuff, thanks for your help. If I need wind in the u and v
directions at various heights (10, 20, 30, 40...1000m) is that possible? I
guess I need to know what data is available with what product. Should I
check the model descriptions for that information? Thanks again.
# ===================
Kyle Shannon
Physical Science Technician
RMRS Fire Sciences Lab
Fire, Fuels & Smoke - RWU 4405
5775 Highway 10 W.
Missoula, MT 59808
(406)646-6577
kshannon@xxxxxxxxx
ksshannon@xxxxxxxxx
# ===================
On Mon, Nov 2, 2009 at 3:54 PM, Robb Kambic <rkambic@xxxxxxxxxxxxxxxx>wrote:
> On Mon, 2 Nov 2009, Kyle Shannon wrote:
>
> Hello everyone,
>> I am trying to use the netCDF subset tools and I was wondering what values
>> are
>> acceptable for the 'vertCoord'
>> variable. Can I specify height above ground level and set vertCoord to n
>> meters above the ground?
>>
>
> Hiya Kyle,
>
> I'm not quite sure I understand your question but the netCDF subset tool
> can only return values that are in the file. For instance, if the file has 2
> meter height above ground level, you can not request 5 meters above ground.
>
> Here's a sample url DGEX_Alaska_12km grid
>
>
> http://motherlode.ucar.edu:8081/thredds/ncss/grid/fmrc/NCEP/DGEX/Alaska_12km/files/DGEX_Alaska_12km_20091101_1200.grib2/dataset.html
>
> Looking at the page, you can see that the values that are acceptable are
> the values next to variable Geopotential_height.
>
> with Vertical Levels (pressure) : 100000.0 85000.0 70000.0 50000.0 25000.0
> Pa
> Geopotential_height
>
> Documentation about vertical coordinates says:
>
> For Grid as Point only , you may specify the vertical coordinate. The
> vertical slice closest to the requested coordinate will be returned. The
> possible vertical coordinates are shown in the Dataset Descriptor document.
> If you specify multiple variables with different vertical coordinates,
> ambiguous results are possible, and you are advised not to use the service
> in this way. If you do, the following rules are used:
>
> 1. Variables are examined in order they appear in the query, and the
> vertical coordinate for the first variable that has one is used.
> 2. The service loops through the levels of that vertical coordinate, and
> for each variable looks for the closest value (ignoring units!!)
> 3. If the value is outside the range for that variable, a missing value
> (NaN) is used.
>
> Example:
>
> * vertCoord=850
>
>
> For more information:
>
> http://www.unidata.ucar.edu/projects/THREDDS/tech/interfaceSpec/NetcdfSubsetService.html
>
> Robb...
>
>
> >
>
>> # ===================
>> Kyle Shannon
>> Physical Science Technician
>> RMRS Fire Sciences Lab
>> Fire, Fuels & Smoke - RWU 4405
>> 5775 Highway 10 W.
>> Missoula, MT 59808
>> (406)646-6577
>> kshannon@xxxxxxxxx
>> ksshannon@xxxxxxxxx
>> # ===================
>>
>>
>>
>
> ===============================================================================
> Robb Kambic Unidata Program Center
> Software Engineer III Univ. Corp for Atmospheric
> Research
> rkambic@xxxxxxxxxxxxxxxx WWW:
> http://www.unidata.ucar.edu/
>
> ===============================================================================
