[gradsusr] WRF query

[Mira Losic]

Roopa,
Here is an excerpt from the WRF user's forum:

U and V are relative to the WRF model grid, so they may need to be rotated
to be relative to the earth. This can be achieved by

Uearth = U*cosalpha + V*sinalpha, and
Vearth = V*cosalpha - U*sinalpha.

Also, be aware that if you want to compare this to observations, these
typically record the direction the wind is blowing from, in degrees from
North, so you need to make sure you compute this from the component
vectors.

The full post is here
http://forum.wrfforum.com/viewtopic.php?f=8&t=3225

Hope this helps,
Mira

> Dear all,
>  This is a query for all WRF users. The WRF manual says that uvmet are the
> u and v components of wind rotated to earth coordinates. Can somebody
> please clarify what is the meaning of "rotated to earth coordinates" If I
> want to extract wind data from a particular simulation whether I should
> use
> uvmet or the general u and v??
>
> Any help / info in this regard will be highly appreciated.
>
> Thanks in advance
>
> Warm Regards
> Roopa
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