[ncl-talk] Vorticity Advection with NCL
Adam Phillips
asphilli at ucar.edu
Tue May 22 09:40:01 MDT 2018
Hi Lara,
You are passing in your original data into advect_variable instead of the
regridded variables. Change this:
adv_vrt = advect_variable(u, v, wr, 1, "vorticity advection",
"(m/s)(s-1)",0)
to this:
adv_vrt = advect_variable(u_reclin, v_reclin, wr_reclin, 1, "vorticity
advection", "(m/s)(s-1)",0)
Gaussian grids are indeed rectlinear grids. See the definition here:
https://www.ncl.ucar.edu/Document/glossary.shtml#RectilinearGrid
If you have any further questions please respond to ncl-talk.
Adam
On Tue, May 22, 2018 at 7:24 AM, Lara Quitián Hernández <
laraquitianhernandez at gmail.com> wrote:
> First of all, I apologize for asking you so many questions and for this
> long email.
>
> I'm trying to interpolate the WRF u,v, relative vorticity to a rectilinear
> grid and use the *advect_variable* on the rectilinear grid. However, I
> have obtained this warning and I do not know how to fixed it: *advect_var:
> Warning: No named dimensions. Can not check grid order.*
>
> After defining the diverse variables, I have performed the regrid in this
> way:
>
>
> *;================================================================================*
> *; Part A: WRF (curvilinear) to Rectilinear regrid variable and generate
> weights *
>
> *;================================================================================*
>
> *;Interpolate the WRF u, v and relative vorticity to a rectilinear grid
> with as fine [or finer] resoultion as the WRF grid*
>
>
> *;---Set up options for regridding*
>
> * InterpMethod= "bilinear" ; define interpolation
> method*
>
> *;---Title and filename options*
>
> * Opt = True*
> * Opt at SrcTitle = "WRF grid" ; optional*
> * Opt at WgtFileName =
> "WRF_to_Rect.WgtFile_"+InterpMethod+"."+nlat+"_x_"+nlon+".nc"*
>
> *;---Source grid options*
> * Opt at SrcFileName =
> "WRF.SCRIP_grid_description."+nlat+"_x_"+nlon+".nc" ; Name of source and*
> * Opt at SrcRegional = True*
> * Opt at SrcGridLat = lat2d*
> * Opt at SrcGridLon = lon2d*
>
> *;---Destination grid options*
> * Opt at DstFileName =
> "Rectilinear.SCRIP_grid_description."+nlat+"_x_"+nlon+".nc" ; destination
> files*
> * Opt at DstGridType = "rectilinear"*
> * Opt at DstGridLat = lat*
> * Opt at DstGridLon = lon*
> * Opt at DstRegional = True*
>
> *;---Specify other options *
> * Opt at ForceOverwrite = True*
> * Opt at InterpMethod = InterpMethod*
>
> *;---Perform the regrid: WRF ==> rectilinear (_reclin)*
> * u_reclin = ESMF_regrid(u, Opt) ; Do the regridding for u *
>
> *;---Use the just generated weight file*
> * v_reclin = ESMF_regrid_with_weights(v,Opt at WgtFileName,False)*
>
> *;---Perform the regrid for wr: WRF ==> rectilinear (_reclin)*
> * wr_reclin = ESMF_regrid_with_weights(wr, Opt at WgtFileName,False) *
>
> Afterwards, I use the *advect_variable:*
>
> ;======================================================================
> ;Use 'advect_variable' on the rectilinear grid
> ;======================================================================
>
> adv_vrt = advect_variable(u, v, wr, 1, "vorticity advection",
> "(m/s)(s-1)",0) ;I use gridType=1. I suppose rectilinear and fixed grid
> are quite similar, or even, the same.
>
> printVarSummary(adv_vrt)
> printMinMax(adv_vrt,0)
> print("----")
>
> Finally, I obtain this results and I do not know if they are correctly
> calculated:
>
> *Variable: u_reclin*
> *Type: float*
> *Total Size: 5972400 bytes*
> * 1493100 values*
> *Number of Dimensions: 3*
> *Dimensions and sizes: [bottom_top | 35] x [lat | 180] x [lon | 237]*
> *Coordinates: *
> * lat: [25.832275390625..40.83070373535156]*
> * lon: [-34.179443359375..-9.305511474609375]*
> *Number Of Attributes: 8*
> * missing_value : 9.96921e+36*
> * remap : remapped via ESMF_regrid_with_weights: Bilinear*
> * _FillValue : 9.96921e+36*
> * stagger : *
> * units : m s-1*
> * description : x-wind component*
> * MemoryOrder : XYZ*
> * FieldType : 104*
> *(0) u_reclin: min=-21.454 max=49.9299*
> *(0) ----*
>
> *Variable: v_reclin*
> *Type: float*
> *Total Size: 5972400 bytes*
> * 1493100 values*
> *Number of Dimensions: 3*
> *Dimensions and sizes: [bottom_top | 35] x [lat | 180] x [lon | 237]*
> *Coordinates: *
> * lat: [25.832275390625..40.83070373535156]*
> * lon: [-34.179443359375..-9.305511474609375]*
> *Number Of Attributes: 8*
> * _FillValue : 9.96921e+36*
> * stagger : *
> * units : m s-1*
> * description : y-wind component*
> * MemoryOrder : XYZ*
> * FieldType : 104*
> * remap : remapped via ESMF_regrid_with_weights: Bilinear*
> * missing_value : 9.96921e+36*
> *(0) v_reclin: min=-51.6305 max=46.8953*
> *(0) ----*
>
> *Variable: wr_reclin*
> *Type: float*
> *Total Size: 5972400 bytes*
> * 1493100 values*
> *Number of Dimensions: 3*
> *Dimensions and sizes: [35] x [lat | 180] x [lon | 237]*
> *Coordinates: *
> * lat: [25.832275390625..40.83070373535156]*
> * lon: [-34.179443359375..-9.305511474609375]*
> *Number Of Attributes: 3*
> * _FillValue : 9.96921e+36*
> * remap : remapped via ESMF_regrid_with_weights: Bilinear*
> * missing_value : 9.96921e+36*
> *(0) wr_reclin: min=-34.6481 max=63.9581*
> *(0) ----*
> *(0) RectilinearGrid: nmsg=180075*
> *(0) ----*
> *(0) advect_var: Warning: No named dimensions. Can not check grid order.*
>
> *Variable: adv_vrt*
> *Type: float*
> *Total Size: 5972400 bytes*
> * 1493100 values*
> *Number of Dimensions: 3*
> *Dimensions and sizes: [35] x [180] x [237]*
> *Coordinates: *
> *Number Of Attributes: 2*
> * long_name : vorticity advection*
> * units : (m/s)(s-1)*
> *(0) vorticity advection ((m/s)(s-1)) : min=-0.0107484 max=0.0109576*
>
> Unfortunately, I also obtain this errors:
>
> (0) is_SCRIP: 'Rectilinear.SCRIP_grid_description.nc' doesn't exist.
> (0) ESMF_regrid_gen_weights: invalid or missing SCRIP source grid file.
>
> And I obtain this three files:
>
>
> *Rectilinear.SCRIP_grid_description.180_x_237.nc
> <http://Rectilinear.SCRIP_grid_description.180_x_237.nc>*
>
> *WRF.SCRIP_grid_description.180_x_237.nc
> <http://WRF.SCRIP_grid_description.180_x_237.nc>*
> *WRF_to_Rect.WgtFile_bilinear.180_x_237.nc
> <http://WRF_to_Rect.WgtFile_bilinear.180_x_237.nc>*
>
> Which file do I have to use to display the vorticity advection? None, I
> suppose. They are all description files, except one.
>
> If you need my script, just tell me.
>
> Thanks in advance.
>
> Regards,
> Lara
>
>
> 2018-05-22 11:08 GMT+02:00 Lara Quitián Hernández <
> laraquitianhernandez at gmail.com>:
>
>> Good morning,
>>
>> Thank you very much. There is only one doubt left unanswered: the *advect_function
>> *requires a *Gaussian, regular o fixed grid*, but not *rectilinear*. Is
>> there any relation between them?
>>
>> Regards,
>> Lara
>>
>> 2018-05-21 19:21 GMT+02:00 Dennis Shea <shea at ucar.edu>:
>>
>>> ESMF 37 was
>>> (a) interpolating u and v onto a rectilinear grid;
>>> (b) calculating divergence using uv2dv_cfd which requires u and v to be
>>> on a rectilinear grid;
>>> (c) interpolating the derived divergence on a rectilinear grid back
>>> onto the original WRF grid
>>>
>>> ---
>>> In your case:
>>>
>>> [1] Interpolate the WRF u, v and relative vorticity to a rectilinear
>>> grid with as fine [or finer] resoultion as the WRF grid
>>> [2] Use 'advect_variable' on the rectilinear grid
>>> [3] interpolate the advected quantity on the rectilinear grid back onto
>>> the original WRF grid
>>>
>>> ---
>>> Caveat: Technically, on a sphere, u and v must be interpolated together
>>> using the 'rotation' angle.
>>> Why? because the new location has a 'slightly' different orientation
>>> relative to the pole(s)
>>>
>>> unew = u*cos(rot) - v*sin(rot)
>>> vnew = u*sin(rot) + v*cos(rot)
>>>
>>> The above approach, independently interpolating u and v ignores the
>>> rotation. It is assumed to be very small.
>>>
>>>
>>>
>>>
>>> On Mon, May 21, 2018 at 3:45 AM, Lara Quitián Hernández <
>>> laraquitianhernandez at gmail.com> wrote:
>>>
>>>> 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
>>>> <https://maps.google.com/?q=Plaza+Ciencias,+1+28040+Madrid.+Spain&entry=gmail&source=g>
>>>> 28040 Madrid. Spain
>>>> <https://maps.google.com/?q=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>
>>
>>
>
>
> --
>
>
> *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>
>
>
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>
>
--
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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