# Can we extrapolate wind speed data to higher altitudes?

I have some data (GRIB layers) about wind components u and v, which I would like to use to estimate wind magnitude and direction. But the model says it is for 10 m altitude.

Is there a way to extrapolate this value for higher altitudes? lets say 600 m. If yes, how? which other variables should I consider that can bias this calculation?

Thanks a lot!

Yes, but it may not be valid. The extrapolation will be valid for about 0.1 * PBL Height using the Log-Wind Profile

You will need:

• PBL Height.
• A second Wind speed (within 0.1*PBL Height)
• Surface Sensible Heat Flux
• Surface Latent Heat Flux
• Potential Temperature

You can use the last three variables to calculate the Monin-Obukhov Length (MOL). Then use the MOL to calculate $\psi$:

If L>0 $\psi=\frac{z}{L}$

If L=0 $\psi=0$

If L<0 $\psi=2\ln(\frac{1+x}{2})+\ln(\frac{1+x^2}{2})-2\tan^{-1}(x)+\frac{\pi}{2}$

where $x=(1-15\frac{z}{L})^{\frac{1}{4}}$

Now that you have $\psi$, you can derive the friction velocity and surface roughness length using the log-wind profile and $\psi(\frac{z}{L})$. Once you have those two, you can extrapolate wind speed 600 meters up, provided the surface layer is that high.