Problem in sst plot
Fil
fil at METEOPT.COM
Wed May 13 21:02:58 EDT 2009
Hi, Diane
Thanks a lot for your help, your solution works perfectly for polar
stereographic projections. But on other projections it still doesn't show
anything from -180º to 0º longitude. If I try to plot just for North
America, I get an "Entire Grid Undefined" message.
With 'set lon -180 180' it only draws from -180º to 0º. With lon 180 540
only draws from 0º to 180º. With lon -360 0 it won't draw anything. And with
0 360 it will draw the entire globe, but with the problem (for me) of
getting centered in lon 180º which cuts Europe in half.
Thanks.
2009/5/13 Diane Stokes <Diane.Stokes at noaa.gov>
> 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.
>>
>
--
Fil - MeteoPT.com
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