Map plot (surfm) of polar regions missing data

Hi all,

I have global model output and am trying to plot the data from a view above the south pole. I am using the surfm function (although using contourfm, or surfacem yields similar results) to plot the data on top of an axes such that:

 axesm('MapProjection','vperspec',...
                    'Frame','on','Grid','on',...
                    'Origin',[-90 0 0],...
                    'MeridianLabel','on','ParallelLabel','on')
 surfm(lat,lon,data)

where:

 lat = 145 x 1 double array (latitude of centre of grid box)
 lon = 192 x 1 double array (longitude of centre of grid box)
 data = 145 x 192 double array (model data)

The output of this results in a map, except that it contains a white 'wedge' at the edge of the dataset (see attached image). This doesn't occur when I plot the data in other plotting programs. Any ideas as to how to get it to plot the edge data and fill this wedge?

I have tried applying the example found at this link to my data, with the same result.

I assume it is a problem with my longitude array (since it is a longitudinal slice), but this is direct output from the model and as mentioned before, works fine with other plotting programs. My longitude array is of the following form:

 lon = [0.9385, 0.9385+1.8750i, ..., 359.0625]

Any help would be greatly appreciated.

Thanks! weirdkhar

Answer 1

[Chad Greene]

Hi Weirdkhar,

First, if you make a lot of maps centered about the South Pole, I recommend initializing with antmap or ncpolarm. It's a bit more streamlined than calling the axesm function with a bunch of arguments.

As for the missing data, a manual fix is to append your lat, lon, and data matrices with an extra column, which will be a copy of the very first column. That process is described here.

[weirdkhar]

Perfect! Thanks Chad. And thanks pointing me in the direction of antmap!

[Chad Greene]

Great!