[ncl-talk] Polar stereographic plots of tripole grids

Thu Sep 19 09:47:29 MDT 2019

Sorry, that should be 'res at gsnAddCyclic = True'.

Dave

On Thu, Sep 19, 2019 at 9:45 AM David Bailey <dbailey at ucar.edu> wrote:

> Hi Abby,
>
> This is always the challenge with tripole grids. Here is an example from a
> CICE run on the MOM6 tripole grid:
>
>
> http://webext.cgd.ucar.edu/MOM/bmom.e20.BMOM.f09_t061.long_run_mct.001/ice/bmom.e20.BMOM.f09_t061.long_run_mct.001-obs/yrs1-100/contour/con_ann_hi_cice.png
>
> I always add 'res at gsnAddCycle = True' to all of my plots, but this
> doesn't quite cover the tripole zipper. The only way to do it is add an
> extra row at the northern edge of the domain.
>
> Dave
>
> On Thu, Sep 19, 2019 at 9:39 AM Abigail Smith via ncl-talk <
> ncl-talk at ucar.edu> wrote:
>
>> Hi Dennis,
>>
>> Thanks for your quick response! And thank you for clarifying about the
>> coordinate variables.
>>
>> However, in the plot you attached there are large gaps in the Arctic
>> Ocean. I realize that this is due to the shape of the grid, but using
>> lat2d/lon2d seems to do a slightly better job of mapping data onto those
>> areas, except for the gap passing through 90 degrees N (as seen in the
>> original pdf that I attached). Do you know if there's a way to maximize the
>> area that the data maps to, such that there are no gaps?
>>
>> Best,
>> Abigail
>>
>> On Wed, Sep 18, 2019 at 9:30 PM Dennis Shea <shea at ucar.edu> wrote:
>>
>>> float siconc(time, lat, lon)
>>> where lat(lat) and lon(lon) are coordinate variables.
>>> There is no need to use @lat2d, @lon2d
>>>
>>> The original file was renamed when I downloaded:
>>>
>>> test.siconc_SIday_BCC-CSM2-MR.nc
>>> <http://secure-web.cisco.com/1ul9UbLFj_X6lncl6JMMTi4Z0LU5goBypbouOMvqKAEissidSQKpjXLz-EwLcj3xMGAUbf7OK-l3t-klD4b2rnt1dNK-_zHMNcI5EbARZMGyYkxMwO9cwRwRB8YYP9NYvGkoyrRXsjo8gAXyO31V5cZp17lv3lLMtlrokhjzZPlWGN8md9hSOw3Wf7trO8o3kwOVEPJuXW77J3JsJ9-QSbco3QxsMKoZbg1n5Bwqwg7EaKVxpbsHjumHA-DgtzW_Wy3-64mGcPvfIvQekJLi7TxRVLrNpm9SBFYJU77LIZ2PX_OSg-WiXuXR-PJgw4TH7L6AtBQqC9tpytJAzU11iwKARvBOeR-z_qZKlrUJZ9Dn3-sVi3cAQrJksvjuzR_8b1RqgPEZnA2aC6AbdMqwkWaPNx97aX3ae0ajtBHKPphzDfS_qg9oQ0TK62DC864Xg/http%3A%2F%2Ftest.siconc_SIday_BCC-CSM2-MR.nc>
>>> <==  siconc_SIday_BCC-CSM2-MR_historical_r1i1p1f1_gn_19000101-19091231.nc
>>> ===
>>> Variable: sic
>>> Type: float
>>> Total Size: 121939200 bytes
>>>             30484800 values
>>> Number of Dimensions: 3
>>> Dimensions and sizes: *[time | 365] x [lat | 232] x [lon | 360]*
>>> Coordinates:
>>>             time: [ 0.5..364.5]
>>>
>>> *           lat: [-81.5..89.5]   <== coordinate variable            lon:
>>> [ 0.5..359.5]  <== coordinate variable*
>>> Number Of Attributes: 11
>>>   standard_name : sea_ice_area_fraction
>>>   long_name : Sea Ice Area Fraction (Ocean Grid)
>>>   comment : Area fraction of grid cell covered by sea ice
>>>   *units : %*
>>>   original_name : CN
>>>   cell_methods : area: mean where sea time: mean
>>>   cell_measures : area: areacello
>>>   history : 2018-11-27T09:03:20Z altered by CMOR: Treated scalar
>>> dimension: 'type'.
>>>   coordinates : type latitude longitude
>>>   missing_value : 1e+20
>>>   _FillValue : 1e+20
>>>
>>>
>>> See attached:
>>>
>>> *%> ncl* siconc.ncl
>>>
>>>
>>> On Wed, Sep 18, 2019 at 2:00 PM Abigail Smith via ncl-talk <
>>> ncl-talk at ucar.edu> wrote:
>>>
>>>> Hi NCL-talk,
>>>>
>>>> I'm attempting to create polar stereographic contour plots of Arctic
>>>> sea ice from various CMIP models on their native grids. Some of the grids
>>>> are tripole, so I end up having the same gap as seen in ice_4.ncl at
>>>> https://www.ncl.ucar.edu/Applications/orca.shtml. I want to remove the
>>>> gap, but the solution in ice_4.ncl uses U-fold grid coordinates, which
>>>> aren't provided for many CMIP models.
>>>>
>>>> I've attached an example script and the plot it produces. The data are
>>>> available for download here:
>>>>
>>>> https://handle-esgf.dkrz.de/lp/21.14100/c55636b2-3c1a-4735-8243-4e62310acbc3
>>>> <https://secure-web.cisco.com/1yJctVysxmtw-Ey_-bTATuatmIfgwB_PPX3DpPQbX966Md4RBVe5Og6JJoKylyKORLv3UywkR6yJay4Uu1hsNPoRfDs4ye7bjONPTKDvuhHiNPaKg2HL1Mn5YV8QjpmQWiHKNT7ZzX5dzGQELsJHuupS6TipNVI7-Y6ksQfzlBw_swbE6N4nu15LKyLloKESepVNAuyYsw24x5__PuDAegxI3aPUT74MGoPraBGT9MMXwUM8YXV9r7aW_0dIkNM8QM_Kt4wSA_9aomjcdRY4ts4W2cWopqO0dnC5Lnn0dQ3iv2i_I2g08x75rzcTf6E8XmuvOXcSJADU-J92vZMxS9Ap1ZNCFu6AxmBRAsJ5aeJclzvolz_yVnsgvGmzL1Sr1cOoQMWAJMF9PWnUYdsO4znxrVkFD-KEOjyh9V70jiw-FI4zRdIOS46KR6xmWtaz1igTiJYFnWkiBOGqPUsUhRw/https%3A%2F%2Fhandle-esgf.dkrz.de%2Flp%2F21.14100%2Fc55636b2-3c1a-4735-8243-4e62310acbc3>
>>>> I'm running ncl version 6.3.0 and not getting any error messages.
>>>>
>>>> Thanks in advance for considering this issue!
>>>>
>>>> Best,
>>>> Abigail Smith
>>>> University of Colorado Boulder
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>
>
> --
>
> David A Bailey
>  email: dbailey_at_ucar.edu
> National Center for Atmospheric Research   phone: 303-497-1737
> PO Box 3000
> fax  : 303-497-1700
> Boulder, CO 80307-3000
>                    http://www.cgd.ucar.edu/staff/dbailey
>

-- 

David A Bailey
 email: dbailey_at_ucar.edu
National Center for Atmospheric Research   phone: 303-497-1737
PO Box 3000
fax  : 303-497-1700
Boulder, CO 80307-3000
                   http://www.cgd.ucar.edu/staff/dbailey
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