Problem in sst plot

[Diane Stokes]

Hi, Filipe.

I recently ran into the same problem with a different dataset on the
same grid.

The spatial resolution the data you are viewing is 1/12 of a degree.
The increment in the xdef and ydef statements of your control file is
0.083.  (That's how the increment is stored in the grib file, so it's
not a result of anything you did wrong).

That increment value is not sufficient to wrap the data completely
around the globe.  You have 4320 points in your xdef:
   4321 x 0.083 = 358.643

If you zoom in on the north pole, you'll see the data displayed does not
extend far enough north either.

If you add a few significant digits to the increment values in your xdef
and ydef statements, eg:

   xdef 4320 linear 0.042000 0.083333
   ydef 2160 linear -89.958000 0.083333

you'll get a more accurate mapping of the data.  The values above will
also bring the left and right edge of the grid sufficiently close that
GrADS will know that the data does wrap the globe.  You'd then be able
to display the field when setting longitude values less than 0 or
greater than 360.

    Diane


Filipe wrote:
> Hello all,
>
> I'm trying to plot sst data from ftp://polar.ncep.noaa.gov/pub/sst/ophi/ ,
> but for some reason I get a white strip at longitude 0º when using nps
> projection, as you can see from this pic:
>
> http://img8.imageshack.us/img8/2815/userlist2.png
>
> When using any other projection, grads only draws from lon > 0º, as you can
> see from these pics:
>
> http://img8.imageshack.us/img8/5487/userlist1.png
> http://img8.imageshack.us/img8/7201/userlist3.png
>
> I don't know what I'm doing wrong, hope someone can help me. I'm using
> latest grib2ctl.pl, wgrib v1.8.0.12x and grads 2.05a (I also tested v1.9 and
> opengrads 2.05). I used the script http://pastebin.com/f3dc65253
>
> Best regards.