# [ncl-talk] Question about addition of coriolis parameter (1Darray) and a variable(4D-aray)

Dennis Shea shea at ucar.edu
Fri Feb 8 08:15:40 MST 2019

```vr(ntim,klev,nlat,mlon)  ==> dimension numbers (0,1,2,3)
flat(nlat)
-----
va = vr + *conform*
<http://www.ncl.ucar.edu/Document/Functions/Built-in/conform.shtml>(vr,
flat, 2) )    ; flat matched the '2-th' dimension of 'vr'

va at long_name = "absolute vorticity"
va at units     = "per second
*copy_VarCoords*
<http://www.ncl.ucar.edu/Document/Functions/Contributed/copy_VarCoords.shtml>(u,
va)

or overwrite rather than create a new variable

vr = vr + *conform*
<http://www.ncl.ucar.edu/Document/Functions/Built-in/conform.shtml>(vr,
flat, 2) )    ; flat matched the '2-th' dimension of 'vr'

vr at long_name = "absolute vorticity"
vr at units     = "per second
*copy_VarCoords*
<http://www.ncl.ucar.edu/Document/Functions/Contributed/copy_VarCoords.shtml>(u,
vr)
"

Good luck

On Fri, Feb 8, 2019 at 2:11 AM Lyndz <olagueralyndonmark429 at gmail.com>
wrote:

> Dear NCL-experts,
>
> I am calculating vorticity tendency using the following equation (also
> attached in this email):
> I want to add the coriolis parameter (1D) and the calculated relative
> vorticity (4D) before calculating its advection. These two parameters have
> dimensions.
>
> [image: Screenshot from 2019-02-08 18-02-16.png]
>
>
> Below is the part  that calculates the vorticity using spherical harmonics
> and the coriolis parameter.
> ;************************************************
> ; variable and file handling
> ;************************************************
>   f   = addfile("../ncep_6h_jan.nc","r")       ; open netcdf file
>   u   = f->U_GRD_2_ISBL(:,:,:,:)            ; pull u off file
>   v   = f->V_GRD_2_ISBL(:,:,:,:)            ; pull v off file
>   u = u(:,:,::-1,:)                         ;for speherical harmonics
>   v = v(:,:,::-1,:)
> ;************************************************
> ; calculate vorticity on a Fixed Grid
> ;************************************************
> *  vr = uv2vrF_Wrap(u,v)*
>   printVarSummary(vr)
>
>   vr at long_name = "vorticity"
>   vr at units     = "per second"
> ;************************************************
> ;calculate coriolis parameter
> ;************************************************
>   lat = vr&lat
> *  flat = coriolis_param(lat)*
>
> [1] I apologize, I think this is a basic question. How do add the coriolis
> parameter to the calculated vorticity? I already know how to get the
> advection, I only got stuck in this part.
>
> I'll appreciate any help.
>
>
> Sincerely,
>
> *Lyndz*
> _______________________________________________
> 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/20190208/974793ed/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Screenshot from 2019-02-08 18-02-16.png
Type: image/png
Size: 42272 bytes
Desc: not available
URL: <http://mailman.ucar.edu/pipermail/ncl-talk/attachments/20190208/974793ed/attachment.png>
```