Winddirection: Rotated LatLonGrid

[Lee Byerle]

Ronny,
Yes, the scalar should be the same.  For the vectors:  one option, while
not the best, is to treat the entire rotated domain as station data.  You
can then plot the u;v "station data" with oacres() and interpolate to a
geographic grid with the resolution of your choice.  More details are in
the GrADS manual under Station Data, or I can provide a sample if you
need.

Lee


> Hi, I am looking for a solution or a GRADS-script for the following
> problem:
>
> I have the windspeed and winddirection in a rotated LatLon grid and I
> want to compute the windspeed and winddirection in the geographical grid.
> I think, that the windspeed (as a skalar) must be the same in both
> grids, but what is with the winddirection?
> It is clear that I can determine the new angle by calculating the u- and
> v-component in the rotated grid and do the rotation backwards and
> calculate then the winddirection.
> But: Is there an easier way to calculate it, without knowing the u and
> v-component?
>
> Thanks for any hints
>
> Ronny
>