Re: Error message concerning latitude and longitude

From: Mary Haley <haley_at_nyahnyahspammersnyahnyah>
Date: Thu Dec 12 2013 - 07:35:35 MST

Dear Stephan,

It looks like you have a curvilinear grid (2D lat/lon arrays). You need to associate rlat/rlon with your data when you call gsn_csm_xxx_map, otherwise NCL won't know where on a map to plot your data.

Try adding these three lines:

  res@sfXArray = f->rlon
  res@sfYArray = f->rlat
  res@gsnAddCyclic = False

Also, since you have a rotated grid, you may want to plot the data in the correct rotated projection. Please see the first (only) example at:

http://www.ncl.ucar.edu/Applications/rotatedltln.shtml

Read the description on the above page about how to get the correct map projection.

I would recommend writing an NCL script in a UNIX editor, rather than trying to do all of this interactively. Once you save the script, calling it something like "plot_temp.ncl", you run it on the UNIX command line with:

    ncl plot_temp.ncl

Good luck,

--Mary

On Dec 12, 2013, at 6:47 AM, Stephan Herrmann <stephan.w.herrmann@t-online.de> wrote:

>
>
> Hello everybody,
>
> I have calculated the mean temperature of Bolivia (1961-1970) with Climate Data Operators. The result is saved in the file: MPIM-REMO_EH5OMA1Br3_HR_044_BOL_1961-1970_167_timemean.nc. I want to plot the result with NCL and get the following error message:
>
> (0) check_for_y_lat_coord: Warning: Data either does not contain a valid latitude coordinate array or doesn't contain one at all.
> lines 1-1/1 (END)
>
> I need the plot for my diploma thesis in Meteorology.
>
> The NCL code is as follows:
>
> Copyright (C) 1995-2013 - All Rights Reserved
> University Corporation for Atmospheric Research
> NCAR Command Language Version 6.1.2
> The use of this software is governed by a License Agreement.
> See http://www.ncl.ucar.edu/ for more details.
>
> ncl 0> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"
> ncl 1> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"
> ncl 2> begin
> ncl 3> f = addfile("MPIM-REMO_EH5OMA1Br3_HR_044_BOL_1961-1970_167_timemean.nc","r")
> ncl 4> T=f->var167(0,0,:,:)
> ncl 5> wks=gsn_open_wks("ps","Bolivia_Timemean_1961-1970")
> ncl 6> res = True
> ncl 7> res@gsnMaximize = True
> ncl 8> res@tiMainString = "Bolivia_Timemean_1961-1970"
> ncl 9> plot = gsn_csm_contour_map(wks,T,res)
> ncl 10> end
>
> I have seen this problem before in this list, but I could not make it work using those tips.
>
> Here are the information about the variable "var167" and the variable "T":
>
> Variable: var167
> Type: float
> Total Size: 18544 bytes
> 4636 values
> Number of Dimensions: 4
> Dimensions and sizes: [time | 1] x [height | 1] x [rlat | 76] x [rlon | 61]
> Coordinates:
> time: [19710101..19710101]
> height: [ 2.. 2]
> rlat: [-20.68..12.32]
> rlon: [157.56..183.96]
> Number Of Attributes: 1
> grid_mapping : rotated_pole
>
> Variable: T
> Type: float
> Total Size: 18544 bytes
> 4636 values
> Number of Dimensions: 2
> Dimensions and sizes: [rlat | 76] x [rlon | 61]
> Coordinates:
> rlat: [-20.68..12.32]
> rlon: [157.56..183.96]
> Number Of Attributes: 3
> height : 2
> time : 19710101
> grid_mapping : rotated_pole
>
> I have renamed rlat to lat and rlon to lon but this does not solve the problem. The error message still occur. I hope you can help me.
>
> Attachment: file MPIM-REMO_EH5OMA1Br3_HR_044_BOL_1961-1970_167_timemean.nc
>
>
> Best regards
>
> Stephan<MPIM-REMO_EH5OMA1Br3_HR_044_BOL_1961-1970_167_timemean.nc>_______________________________________________
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Received on Thu Dec 12 07:35:46 2013

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