[MITgcm-support] Initial Wind on Cubed Sphere

[Chris Watkins]

Hi Jean-Michel,

Thank you for such a quick response. I was looking at
utils/matlab/cs_grid/uvLatLon2cube.m. It asks for spv as one of its input.
Can you tell me what spv is?

Thanks again,

Chris

On 1 May 2012 16:11, Jean-Michel Campin <jmc at ocean.mit.edu> wrote:

> Hi Chris,
>
> Depending on the wind field, you may try one of the 2 methods:
> 1) general method (similar to what is done within matlab script
>  utils/matlab/cs_grid/uvLatLon2cube.m): your can define your wind field
>  on a lat-lon grid and then use uvLatLon2cube.m to interpolate + rotate
>  to CS-grid direction + put the uVel,vVel on to C-grid location;
> Or, you can skip the interpolation stage and define your wind field
>  on the CS-grid, at the grid-cell center location and then just do
>  the rotation + the move to C-grid location.
> 2) specific method for non-divergent wind-field (this is a special case
>  which is not uncommon): From the analytical expression of the wind,
>  you can derive an analytical expression of the horizontal stream-function.
>  Then you evaluate the stream-function on the CS-grid at the grid-cell
> corner
>  (position XG,YG) and from there you can compute directly the wind
>  at the C-grid location (this ensure that uVel,vVel field is non
> divergent).
>  There are few matlab scripts that uses this 2nd method (e.g., in
>  MITgcm_contrib/dyncore_ASP/mat_scripts ) and also some fortran code
>  (e.g., verification/advect_cs/code/ini_vel.F or
>   verification/code/solid-body.cs-32x32x1/code/ini_vel.F).
>
> Cheers,
> Jean-Michel
>
> On Tue, May 01, 2012 at 02:34:45PM +0100, Chris Watkins wrote:
> > I am trying to set up an initial wind field using the file ini_vel.f on a
> > cubed sphere. I know analytically what the meridional and zonal winds
> > should be on a latitude-longitude grid. Can anyone help me understand
> what
> > adjustments I need to make to these values to make them into the uVel and
> > vVel variables.
> >
> > I originally set uVel to the zonal wind and vVel to the meridional wind
> but
> > the output for U & V  for timestep 0 does not match.
> >
> > --
> > Chris Watkins
>
> > _______________________________________________
> > MITgcm-support mailing list
> > MITgcm-support at mitgcm.org
> > http://mitgcm.org/mailman/listinfo/mitgcm-support
>
>
> _______________________________________________
> MITgcm-support mailing list
> MITgcm-support at mitgcm.org
> http://mitgcm.org/mailman/listinfo/mitgcm-support
>



-- 
Chris Watkins

G+ GPlus.to/ChrisWatkins <http://gplus.to/ChrisWatkins>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mitgcm.org/pipermail/mitgcm-support/attachments/20120501/84176f97/attachment.htm>