WAsP Prediction - Distance Limitation

[Dhanraj]

Hi;

As it relates to using WAsP to predict the wind climate at a candidate site using the observed wind climate at a reference site, is there a limit to the distance between these two sites for which WAsP can accurately make such prediction?

What is this distance?

Beyond this distance limit, what is the estimated increase in prediction error?

I read in an old post, dated sometime back in 2006, prediction can be between 0 and 50 km. Is there any reference to support this?

Thank you.

[Rogier]

Hi Dhanraj,
No the distance up to which a observed wind climate is valid depends mostly on the complexity and similarity of the terrain and on mesoscale wind effects. Dependent on those two factors can vary indeed roughly between 0 an 50 km. As far as I know there is no reference for this, it is just based on the physical assumptions used in the model. You can check mesoscale gradients in wind speed on the global wind atlas (https://globalwindatlas.info), which is based on simulations with a resolution of 9 km. So even with that resolution it is still possible that some mesoscale effects are not fully resolved. Regarding microscale effects we usually use the 'similarity principle': if sites are very similar in type of terrain you can extrapolate over larger distances, if not, the distance becomes smaller.

[Dhanraj]

Thank you Rogier.