[MITgcm-support] cartesian grid

[Himansu Pradhan]

thank you Sir for your hints/suggestion .

it helped and finally worked...

On Mon, Aug 6, 2012 at 5:30 PM, Martin Losch <Martin.Losch at awi.de> wrote:

> Himansu,
>
> the model really only knows two horizontal direction: the i-direction and
> the j-direction. (for curvilinear grids you can give it the actual
> coordinates etc, but that's even more complictated than what you need). So
> you have to give the model the wind in the i-direction
> ("taux"=zonalWindFile, ) and the j-direction ("tauy"=meridWindFile,), the
> naming is admittedly a little unfortunate.
> I mean that you have to rotate your wind vector (I asume with east-west
> and north-south components) according the orientation of the your grid.
>
> vectorOnGrid = RotationMatrix*vectorOnLatLon, which rotationMatrix =
> (cos(phi) sin(phi); -sin(phi) cos(phi)). where phi the angle between north
> and your grid north. Don't nail me down on indices and direction of
> rotation (you can look that up in any linear algebra book) ...
>
> Martin
>
>
> On Aug 6, 2012, at 1:44 PM, Himansu Pradhan wrote:
>
> > Hello MITgcm users,
> >
> > I am using "Cartesian Grid" in the model. The Wind stress field  in my
> model domain looks like figure feb_tech.jpg (monthly climatological wind
> stress)
> >
> > Plotting the same Wind Stress field in matlab (before making Input
> binary files) the plot looks like Input.jpg. (attached below both the
> figures)
> >
> > In Comparing both the plots it is seen , that the DIRECTION OF THE
> VECTORS of figure "Input.jpg" has been rotated (clearly seen in SOUTHERN
> region) . this means that i am providing wrong WIND STRESS (Input) to the
> MODEL.
> >
> > I want to know how other modelers (those using Cartesian coordinates in
> the MODEL) deals with it  ???? / Should i rotate my model domain (how to do
> this in the MODEL)????? / Or any kind of suggestion/help
> >
> > Thanking all in advance,
> >
> > -himansu
> > <feb_tech.jpg><Input.jpg>_______________________________________________
> > MITgcm-support mailing list
> > MITgcm-support at mitgcm.org
> > http://mitgcm.org/mailman/listinfo/mitgcm-support
>
>
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