[ncl-talk] Vorticity Advection with NCL
Dennis Shea
shea at ucar.edu
Wed May 23 21:03:04 MDT 2018
[0]
You can advect *any *quantity. I thought it is best to advect relative
vorticity and then add the coriolis force to get the 'new' absolute
vorticity. However, you could advect absolute vorticity for you needs. Good
question for your advisor. :-)
[1]
You are starting with a WRF grid. The 'advect_variable' function requires a
rectilinear grid. Hence, you need to generate a weight file that takes data
on a WRF grid to a rectilinear grid. Any name can be used for the weight
file. This is fine:
"WRF_to_Rect.WgtFile_"+InterpMethod+"."+nlat+"_x_"+nlon+".nc"
[2]
Now you want to take the advected vorticity on a rectilinear grid and
interpolate it to the original WRF grid. The following name is fine.
Opt at WgtFileName =
"Rect_to_WRF.WgtFile_"+InterpMethod+"."+nlat+"_x_"+nlon+".nc"
---
You wrote: "I'm still obtaining errors." However, you did not state what
the errors are.
I think the following
adv_wrf = ESMF_regrid(adv_vrt,
* Opt)*
*should be*
adv_wrf = ESMF_regrid(adv_vrt,*
Opt at WgtFileName*)
---
You did not "ftp a WRF file"
Good Luck
On Wed, May 23, 2018 at 4:30 AM, Lara Quitián Hernández <
laraquitianhernandez at gmail.com> wrote:
> Thank you so much. I was absolutely wrong and I did not realize my mistake.
>
> I attach here my script because I'm still obtaining errors and I'm afraid
> I do not fully understand the procedure of the different calculations. For
> example, I do not know if I have to generate a weight file for regridding
> the relative vorticity (wr) or which name give to that weight file
> (Opt at WgtFileName). Moreover, I do not know why do I have to use the
> relative vorticity and not the absolute vorticity to study the vorticity
> advection at the end.
>
> On the other hand, I will also ftp a WRF file and my script.
>
> Thanks in advance.
>
> Regards,
> Lara
>
>
> 2018-05-22 17:40 GMT+02:00 Adam Phillips <asphilli at ucar.edu>:
>
>> 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
>>>> <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
>>> <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>
>>>
>>>
>>> _______________________________________________
>>> 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>
>>
>
>
>
> --
>
>
> *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>
>
>
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