RIX (2004-05-17)

[Old Forum Archivist]

Hi,

I've read in two conference proceedings ("Exploring the limits of wasp" (Bowen & Mortensen, ewec, Goteborg 1996) and

in "Influence of topographical input data on the accuracy of wind flow modelling in complex terrain"

(Mortensen & Petersen, ewec, Dublin 1997)) that delta rix factor should be used as a wasp prediction

error calibrator.

In order to correct wasp predictions, I'd like to know how use it properly.

In particular, I was studying a case with two met station with contemporary data over a period of 1 year.

The two met station are 30 e 40 meters tall each one, and the 10 minutes cross correlation factor is 0.862, so they are

well correlated.

Delta rix value is 2.96% and the error between the estimated mean-wind speed and the observed mean-wind speed

at the same predicted site is 23%.

regards

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Andrea, sorry for the very late answer to your post...



Most likely, the delta_RIX value does not (alone) explain the discrepancy between predicted and observed wind climates in your case. There can be many other explanations for prediction errors and it would take a closer look and some analyses to investigate the reason(s) for the error in your case.



Until now, there has been no 'standard' way of applying the RIX analysis for correction of prediction errors. At the 2006-EW-C conference in Athens there will be a paper about this issue, including an updated procedure for making the RIX analysis and a proposal for a correction procedure.



The WAsP Team @ Risø


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