Re: problems with lat and lon CMIP5 data (regridding)

The problem is that you are using "i" and "j" on the file for the lat/lon
input grid, and these are just index values.

If you look at your data with printVarSummary, you will see a "coordinates"
attribute equal to "lat lon". This tells you that the file should contain
variables "lat" and "lon" on the file. You need to read these and use them
in the linint2_Wrap program. See attached.

I also cleaned up your plotting program, because you had this code, which
doesn't make any sense:

t!0="TIME"
t!1="Y2DEG"
t!2="X2DEG"
lat=t!2
lon=t!1

Since you are regridding to a rectilinear grid, you shouldn't need to do
anything with the named dimensions or coordinate arrays. When you read in
the variable, the coordinate arrays will be attached to the variable, and
the NCL plotting program will see this and use them.

I created an ESMF version of your regridding so you could compare the
different methods. The ESMF script does the regridding and plotting in one
script.

--Mary


On Sat, Jun 14, 2014 at 7:42 AM, Vanúcia Schumacher <
vanucia-schumacher@hotmail.com> wrote:

> Hi users,
>
> I need to change resolution grid data to 2x2, but when the data changes,
> not plotam nothing in the graphic, or plotam strangely, SST data over the
> continent, very crazy! I think the problem is in how the data lat and lon
> are in the original data are not linear, increase and decrease.
> Anyone know how to help me solve this problem?
>
> ncview original data:
> lat =
> 76.3555, 76.29813, 76.23743, 76.17345, 76.10631, 76.03609, 75.9629,
> 75.88685, 75.80793, 75.72632, 75.64211, 75.55537, 75.46625, 75.37481,
> 75.28114, 75.18538, 75.08758, 74.98788, 74.88635, 74.78318, 74.67834,
> 74.57199, 74.46423, 74.35518, 74.24488, 74.13348, 74.021, 73.9076,
> 73.79334, 73.67832, 73.56266, 73.44637, 73.32957, 73.21239, 73.09487,
> 72.97706, 72.85907, 72.741, 72.62287, 72.50481, 72.38686, 72.26913,
> 72.15161, 72.03442, 71.91764, 71.80134, 71.68554, 71.57033, 71.45573,
> 71.34185, 71.22874, 71.11639, 71.00497, 70.89444, 70.78489, 70.67636,
> 70.56889, 70.46255, 70.35738, 70.25343, 70.15072, 70.04929, 69.94922,
> 69.85054, 69.75326, 69.65746, 69.56313, 69.47035, 69.37914, 69.28954,
> 69.20152, 69.11521, 69.03059, 68.94769, 68.86656, 68.78719, 68.70966,
> 68.63393, 68.56007, 68.48814, 68.41808, 68.34997, 68.2838, 68.2196,
> 68.15743, 68.09725, 68.03913, 67.98302, 67.92903, 67.87708, 67.82724,
> 67.77953, 67.73394, 67.6905, 67.64921, 67.61011, 67.57315, 67.53839,
> 67.50585, 67.47548, 67.44734, 67.42143, 67.39776, 67.3763, 67.35709,
> 67.34013, 67.32541, 67.31296, 67.30275, 67.29481, 67.28914, 67.28571,
> 67.28455, 67.28564, 67.289, 67.29462, 67.3025, 67.31262, 67.32501,
> ......
> The values ​​of lat and lon start in 76.3555, and decrea=
se and then
> increase again!
>
> When interpole for new resolution grid, I believe that NCL not do right
> for these values ​​of lat and lon.
>
>
> *Variable: var*
> Type: float
> Total Size: 39049920 bytes
> 9762480 values
> Number of Dimensions: 3
> Dimensions and sizes: [time | 360] x [i | 149] x [j | 182]
> Coordinates:
> time: [15.5..10934.5]
> i: [1..149]
> j: [1..182]
> Number Of Attributes: 12
> standard_name : sea_ice_thickness
> long_name : Sea Ice Thickness
> comment : the mean thickness of sea ice in the ocean portion of the
> grid cell (averaging over the entire ocean portion, including the ice-fre=
e
> fraction). Reported as 0.0 in regions free of sea ice.
> units : m
> original_name : iicethic
> cell_methods : time: mean (interval: 30 minutes) area: mean where sea
> cell_measures : area: areacello
> history : 2011-11-11T12:43:09Z altered by CMOR: replaced missing value
> flag (9.96921e+36) with standard missing value (1e+20).
> missing_value : 1e+20
> _FillValue : 1e+20
> associated_files : baseURL:
> http://cmip-pcmdi.llnl.gov/CMIP5/dataLocation gridspecFile:
> gridspec_seaIce_fx_IPSL-CM5A-LR_decadal1980_r0i0p0.nc areacello:
> areacello_fx_IPSL-CM5A-LR_decadal1980_r0i0p0.nc
> coordinates : lat lon
>
> *Variable: new_var*
> Type: float
> Total Size: 23328000 bytes
> 5832000 values
> Number of Dimensions: 3
> Dimensions and sizes: [time | 360] x [lat | 90] x [lon | 180]
> Coordinates:
> time: [15.5..10934.5]
> lat: [-87.86..87.86]
> lon: [ 0..358]
> Number Of Attributes: 12
> standard_name : sea_ice_thickness
> long_name : Sea Ice Thickness
> comment : the mean thickness of sea ice in the ocean portion of the
> grid cell (averaging over the entire ocean portion, including the ice-fre=
e
> fraction). Reported as 0.0 in regions free of sea ice.
> units : m
> original_name : iicethic
> cell_methods : time: mean (interval: 30 minutes) area: mean where sea
> cell_measures : area: areacello
> history : 2011-11-11T12:43:09Z altered by CMOR: replaced missing value
> flag (9.96921e+36) with standard missing value (1e+20).
> missing_value : 1e+20
> _FillValue : 1e+20
> associated_files : baseURL:
> http://cmip-pcmdi.llnl.gov/CMIP5/dataLocation gridspecFile:
> gridspec_seaIce_fx_IPSL-CM5A-LR_decadal1980_r0i0p0.nc areacello:
> areacello_fx_IPSL-CM5A-LR_decadal1980_r0i0p0.nc
> coordinates : lat lon
>
> my code:
>
> begin
>
> fils = systemfunc("ls *.nc")
>
> f = addfiles(fils, "r")
>
> ListSetType(f,"join")
>
> var = f[:]->sit
>
> var!0="time"
> var!1="i"
> var!2="j"
>
> newfile = "sit1.nc"
>
> system("rm -f "+newfile)
>
> file_create = addfile(newfile, "c") ;criando arquivo.
>
> new_lon = fspan(0, 358, 180) ; usually no cyclic point
> new_lon@units = "degrees_east"
> new_lon!0 = "lon"
>
> new_lat = fspan(-87.86, 87.86, 90)
> new_lat@units = "degrees_north"
> new_lat!0 = "lat"
>
> new_var = linint2_Wrap(var&j,var&i,var,True,new_lon,new_lat,0)
>
> file_create->media = new_var
>
> end
>
>
> Vanúcia Schumacher
>
>
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Received on Thu Jun 19 05:09:52 2014