[ncl-talk] About Hodograph
isakhar sakhar isakhar
isakhar.inside13 at gmail.com
Tue Nov 17 20:55:25 MST 2015
Dear Mr. Adam
So far I am using the script (in attachment) to find wind direction and
wind speed in 10 meter height. But when I tried to find wind speed in 30
meter, 50 meter or 100 meter, I get the same result as 10 meter height.
---------------------------------------------------------------------------------------------------------------------------------------
plane = (/ 0., 10./) ; height levels to plot - in meter
; Interpolate U,V to 0 Meters
u_plane = wrf_user_intrp3d( u,height,"v",plane,0.,False)
v_plane = wrf_user_intrp3d( v,height,"v",plane,0.,False)
; Calculate Wind Speed from Vectors
spd = (u_plane*u_plane + v_plane*v_plane)^(0.5)
windspd0(it)=spd(x,y)
; Wind direction at 10 Meters
r2d = 45.0/atan(1.0) ; conversion factor
(radians to degrees)
dir = atan2(u_plane,v_plane) * r2d + 180
dir0(it) = dir(x,y)
; Wind Speed
spd at description = "Wind Speed"
spd at units = "m/s"
u_plane at units = "m/s"
-------------------------------------------------------------------------------------------------------------------------------------
I tried to change height level in function plane = (/ 0., 10./) to (/ 0.,
30./) or (/ 0., 50./), or (/ 0., 100./) but I still get the same wind speed.
I also tried to change plane = (/ 10., 30./) for 30 meter height but I get
error.
Because now I am really interesting to know wind speed and direction in 30
meter, 50 meter, and 100 meter height.
Is there anything still wrong with this script ?
Thank you,
Soares
On Mon, Nov 9, 2015 at 9:41 PM, Adam Phillips <asphilli at ucar.edu> wrote:
> Hi Soares,
> The error message:
> fatal:["Execute.c":5900]:variable (time) is not in file (infile)
> is telling you exactly what the issue is. By examining your input WRF file
> you can see that a variable time is not present, but a variable names Times
> is. The error message is coming from this line:
> time = infile->time
>
> However, note that you do not need to exactly follow the example coding
> Amadou pointed you to. You do not necessarily need to read in time, or
> wind_speed and wind_direction. (Your file doesn't have those three
> variables anyway.) All you should be doing is reading in the winds at the
> level you are interested in (either U10/V10 or U/V), choose the grid point
> you are interested in, and pass the wind speed and direction to the
> create_one_station_plot function.
>
> wrf_ll_to_ij might be useful to find the nearest coordinate indexes to a
> desired latitude and longitude:
> http://www.ncl.ucar.edu/Document/Functions/Built-in/wrf_ll_to_ij.shtml
>
> a list of all WRF functions available in NCL is also given here:
> http://www.ncl.ucar.edu/Document/Functions/wrf.shtml
>
> Hope that all helps. If after modifying your script as detailed above you
> still have questions about how to read in and subset your WRF data I highly
> advise you to look at the online documention including the WRF online NCL
> tutorial and the NCL website:
> http://www2.mmm.ucar.edu/wrf/OnLineTutorial/Graphics/NCL/NCL_examples.htm
> http://www.ncl.ucar.edu/Applications/wrf.shtml
>
> Adam
>
>
>
>
>
>
> On Sun, Nov 8, 2015 at 7:03 PM, isakhar sakhar isakhar <
> isakhar.inside13 at gmail.com> wrote:
>
>> Dear Mr. Adam and Mr.Amadou
>>
>> I just downloaded the file as you recommend and made some change
>> according to my configuration. But after running the simulation, I get
>> error says "fatal:["Execute.c":5900]:variable (time) is not in file (infile)
>> ".
>>
>> Now I don't have any station (weather station), just a computer for
>> running simulation only because I see there are 5 stations inside the
>> script.
>>
>> Here I attach my two files, one is my hodograph modification and one is
>> my ncdump file.
>> Please take a look of these files.
>>
>> Regards,
>> Soares
>>
>> On Fri, Nov 6, 2015 at 4:11 PM, Adam Phillips <asphilli at ucar.edu> wrote:
>>
>>> Hi Soares,
>>> It looks to me like all you attached are functions. I do not see a
>>> script that calls the hodograph function for instance. You need to call
>>> hodograph from another NCL script, passing in the workstation, an array of
>>> the wind speed, an array of the direction, and a resource list.
>>>
>>> For an example of how to do this, refer to a ncl-talk question from a
>>> couple weeks back:
>>> http://mailman.ucar.edu/pipermail/ncl-talk/2015-October/004199.html
>>>
>>> And see the second attachment on that page:
>>>
>>> http://mailman.ucar.edu/pipermail/ncl-talk/attachments/20151022/9bdf6ef5/attachment.obj
>>>
>>> Coincidentally, this script holds a function that creates a hodograph
>>> (named create_one_station_plot), and that function is called at the
>>> bottom of the main script.
>>>
>>> Note that you do not have to use the ncl-talk script to do what you
>>> want. This just provides an example where someone was creating hodographs
>>> by calling a function external to the main script.
>>>
>>> Finally, no, at present there are not any hodograph examples on the NCL
>>> website.
>>>
>>> Hope that helps. If not, or if you have any further questions, please
>>> respond to the ncl-talk email list.
>>> Adam
>>>
>>>
>>>
>>>
>>>
>>> On Fri, Nov 6, 2015 at 12:07 AM, isakhar sakhar isakhar <
>>> isakhar.inside13 at gmail.com> wrote:
>>>
>>>> Dear NCL Talk Team
>>>>
>>>> I want to plot Hodograph by using 2 files in attahment but I did not
>>>> see anything, no plotting.
>>>>
>>>> I tried also to find hodograph in website "
>>>> https://www.ncl.ucar.edu/Applications/ " but I could not see it.
>>>>
>>>> Can someone help me how to plot wind speed and direction in Hodographs?
>>>>
>>>> Thank you,
>>>> Soares
>>>>
>>>> _______________________________________________
>>>> ncl-talk mailing list
>>>> ncl-talk at ucar.edu
>>>> List instructions, subscriber options, unsubscribe:
>>>> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
>>>>
>>>>
>>>
>>>
>>> --
>>> Adam Phillips
>>> Associate Scientist, Climate and Global Dynamics Laboratory, NCAR
>>> www.cgd.ucar.edu/staff/asphilli/ 303-497-1726
>>>
>>> <http://www.cgd.ucar.edu/staff/asphilli>
>>>
>>
>>
>
>
> --
> Adam Phillips
> Associate Scientist, Climate and Global Dynamics Laboratory, NCAR
> www.cgd.ucar.edu/staff/asphilli/ 303-497-1726
>
> <http://www.cgd.ucar.edu/staff/asphilli>
>
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