[ncl-talk] Vorticity Advection with NCL

[Lara Quitián Hernández]

Good morning,

Thank you so much. Unfortunately, I have some doubts.

1.- I have read the information for Example 37 but I do not understand the
need of computing the divergence ("uv2dv_cfd"). I just need my variables on
a Gaussian, regular o fixed grid in order to apply the *advect_variable*
function
2.- I need to convert my curvilinear WRF grid to a Gaussian, regular o
fixed grid. However, in both Examples (29a and 37) a regrid from a WRF grid
to a rectilinear grid is carried out. Are those grids (Gaussian, regular o
fixed grid) also rectilinear grids?
3.-Do I need to regrid back to the WRF curvilinear grid as it is done in
both examples?

Thanks in advance.

Regards,
Lara



2018-05-20 1:10 GMT+02:00 Dennis Shea <shea at ucar.edu>:

> NCL has no builtin function to advect a field (eg: vorticity) on a
> curvilinear grid (eg: your WRF Grid)..
> Maybe ask wrfhelp?
>
> ===
> That said
>
> https://www.ncl.ucar.edu/Applications/ESMF.shtml
> Example 29a
> or, maybe better,
> Example 37
>
> outlines a method that might be used for your needs.
>
> ===
> Good luck
>
>
> On Wed, May 16, 2018 at 7:40 AM, Lara Quitián Hernández <
> laraquitianhernandez at gmail.com> wrote:
>
>> Hello,
>>
>> Thank you. In the case of calculating the horizontal advection for
>> *vorticity*, it would be better to use the direct WRF variable ( vo =
>> wrf_user_getvar(a,"*avo*",-1)) or define it via different functions:
>> https://www.ncl.ucar.edu/Applications/vort.shtml
>>
>> The only example in the link defines the Vorticity like this:
>>
>> ;************************************************
>> ; calculate vorticity on a Gaussian Grid
>> ; scale for visual convenience
>> ;************************************************
>>   scale = 1.e05
>>   vrt   = u                                      ; retain coordinates
>>   vrt   = uv2vrG_Wrap(u,v) * scale
>>   vrt at long_name = "vorticity"
>>   vrt at units     = "scaled"
>>
>>
>> However, my simulations are generated on a Lambert Conformal grid
>> projection, not Gaussian one. Does this change the procedure to calculate
>> it?
>>
>> Regards,
>> Lara
>>
>> 2018-05-16 14:28 GMT+02:00 Dennis Shea <shea at ucar.edu>:
>>
>>> Maybe:
>>>
>>> https://www.ncl.ucar.edu/Document/Functions/Contributed/adve
>>> ct_variable.shtml
>>>
>>> 'x' would be vorticity
>>>
>>> Good Luck
>>>
>>> On Wed, May 16, 2018 at 4:01 AM, Lara Quitián Hernández <
>>> laraquitianhernandez at gmail.com> wrote:
>>>
>>>> Good morning,
>>>>
>>>> I would like to know if there is a possibility of calculating the
>>>> Vorticity Advection with NCL.
>>>>
>>>> Thanks in advance.
>>>>
>>>> Regards,
>>>> Lara
>>>>
>>>>
>>>> --
>>>>
>>>>
>>>> *Lara Quitián Hernández, PhD Student*
>>>> Departamento de Física de la Tierra, Astronomía y Astrofísica
>>>> Facultad de Ciencias Físicas
>>>> Ciudad Universitaria, Plaza Ciencias, 1
>>>> <https://maps.google.com/?q=Ciudad+Universitaria,+Plaza+Ciencias,+1+28040+Madrid.+Spain&entry=gmail&source=g>
>>>> 28040 Madrid. Spain
>>>> <https://maps.google.com/?q=Ciudad+Universitaria,+Plaza+Ciencias,+1+28040+Madrid.+Spain&entry=gmail&source=g>
>>>> Email: lquitian at ucm.es <mlunar at aemet.es>
>>>>
>>>>
>>>> _______________________________________________
>>>> ncl-talk mailing list
>>>> ncl-talk at ucar.edu
>>>> List instructions, subscriber options, unsubscribe:
>>>> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
>>>>
>>>>
>>>
>>
>>
>> --
>>
>>
>> *Lara Quitián Hernández, PhD Student*
>> Departamento de Física de la Tierra, Astronomía y Astrofísica
>> Facultad de Ciencias Físicas
>> Ciudad Universitaria, Plaza Ciencias, 1
>> <https://maps.google.com/?q=Ciudad+Universitaria,+Plaza+Ciencias,+1+28040+Madrid.+Spain&entry=gmail&source=g>
>> 28040 Madrid. Spain
>> <https://maps.google.com/?q=Ciudad+Universitaria,+Plaza+Ciencias,+1+28040+Madrid.+Spain&entry=gmail&source=g>
>> Email: lquitian at ucm.es <mlunar at aemet.es>
>>
>>
>


-- 


*Lara Quitián Hernández, PhD Student*
Departamento de Física de la Tierra, Astronomía y Astrofísica
Facultad de Ciencias Físicas
Ciudad Universitaria, Plaza Ciencias, 1
28040 Madrid. Spain
Email: lquitian at ucm.es <mlunar at aemet.es>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.ucar.edu/pipermail/ncl-talk/attachments/20180521/a9b023e6/attachment.html>