[ncl-talk] How do I get North to be Up For my Plots of WRF Data?

[Mary Haley]

Ronald,

As Barry mentioned, it would help if we could see your script and a sample
image. When you say north is "up and right" this sounds like you might have
some kind of rotated lat/lon projection.

Also, are you using the wrf_contour, wrf_vector, and/or wrf_map_overlays to
plot your data? If so, then be aware that these functions use whatever
native map projection is defined on your WRF file, and you will not be able
to change this.

If you want to change the map projection, then you need to use either the
gsn_csm_contour_map or gsn_csm_vector_map function, depending on whether
you are drawing contours or vectors, *and* you will need to provide the lat
/ lon coordinates to these functions via the special lat2d / lon2d
attributes.

You can see some examples of using the wrf_xxxx functions versus the
gsn_csm_xxxx_map functions at:

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

In particular, look at the the first example, wrf_gsn_1.ncl and
wrf_nogsn_1.ncl.  In the wrf_gsn_1.ncl example, you'll see how it reads the
XLAT / XLONG variables off the WRF file and attaches them to the "hgt"
variable, via:

  hgt at lat2d = wrf_user_getvar(a,"XLAT",it)   ; latitude/longitude
  hgt at lon2d = wrf_user_getvar(a,"XLONG",it)  ; required for plotting

By doing this, you can choose whatever map projection you want. This
particular example uses a simple lat/lon projection, also known as a
cylindrical equidistant projection.

--Mary


On Sun, Feb 11, 2018 at 7:58 PM, Ronald Stenz <rds238 at cornell.edu> wrote:

> I must be missing something simple, but I can't figure out how to get
> North to be Up for my WRF plots.  Currently, no matter what I do, north
> always ends up being towards the upper right in my plots (regardless of
> what map projection I use).  I just looked to provide the link for where I
> got the base NCL plotting codes, but I can't seem to find it anymore on
> google and it looks like newer versions of codes now exist?  Will switching
> to these new NCL graphics codes for WRF allow me to do this, or is this
> something that should work with the codes I already have?
>
> If so, how do I get North to be Up in my plots, and not up and right?
>
> Thanks
>
>
> <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=icon> Virus-free.
> www.avast.com
> <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=link>
> <#m_1797275528208953350_DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>
>
> _______________________________________________
> ncl-talk mailing list
> ncl-talk at ucar.edu
> List instructions, subscriber options, unsubscribe:
> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.ucar.edu/pipermail/ncl-talk/attachments/20180213/c127277e/attachment.html>