[ncl-talk] A question about computing the divergence given the WRF output file

[Dennis Shea]

[0] wrfhelp would likely be the best place to ask about this.
---
[1] Attached are some fortran subroutines to calculate various quantities
using WRF data.
   wrf_curl_div.f: http://forum.wrfforum.com/viewtopic.php?f=32&t=2267
   wrf_vort.f:
http://mailman.ucar.edu/pipermail/ncl-talk/2014-November/001483.html

These can be invoked from an NCL script by using WRAPIT:
   https://www.ncl.ucar.edu/Document/Tools/WRAPIT.shtml
Likely, you can ignore warning messages.

%> WRAPIT wrf_curl_div.f
%> WRAPIT wrf_vort.f


NOTE: these were *not written or tested* by NCL developers. Hence, they are
*not supported*.

==================
[2] An alternative that may be adequate if the divergence is being
calculated for visual purposes is:

   https://www.ncl.ucar.edu/Applications/ESMF.shtml

   (a) interpolate the zonal and meridional wind components to a
rectilinear grid;
   (b) Use the *uv2dv_cfd*
<https://www.ncl.ucar.edu/Document/Functions/Built-in/uv2dv_cfd.shtml>
function to compute divergence on the rectilinear grid;
   (c) interpolate the derived divergence (b) onto the original WRF grid.

Good Luck






On Mon, Jan 22, 2018 at 1:44 AM, 古枫玥瑟 via ncl-talk <ncl-talk at ucar.edu>
wrote:

> Dear ncl-talk,
> There are 3 functions to compute the divergence. They are uv2dvF
> <http://www.ncl.ucar.edu/Document/Functions/Built-in/uv2dvF-1.shtml>,
> uv2dv <http://www.ncl.ucar.edu/Document/Functions/Built-in/uv2dvF-1.shtml>
> G,uv2dv_cfd
> <http://www.ncl.ucar.edu/Document/Functions/Built-in/uv2dv_cfd.shtml>.
> I would like to know which function should I use to compute the
> divergence given WRF output file (eg. wrfout_d03_2016-08-11_00:00:00)
> because the number of dimensions of the lat/lon is 2 ?
> Then how to write the code? Thank you!
>
>
>                               Many thanks in advance
>
> Regards
>
> Yan
>
> Shanghai Institute of Meteorology,China.
>
>
>
>
>
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