Range Statistics as Estimators of Intensity of Turbulence at Diablo Canyon

Abstract

Simultaneous measurements of the standard deviation of the azimuth and vertical wind direction fluctuations from a digital recording system and the range in wind direction fluctuations from an analog recording system have been used to determine the scaling factor required for converting the range data to estimates of standard deviations. In general, the study shows that constant scaling factors used in estimating the standard deviation from the range of wind direction fluctuations are representative of the median values of the standard deviation. However, the standard deviation is likely to be underestimated during periods of stable atmospheric conditions and slightly overestimated during neutral through unstable atmospheric conditions. The results also indicate that the conversion of analog readings to standard deviations, using the range in wind direction fluctuations, is sensitive to recorder response, data reduction techniques and scale of turbulence. As a result, the scaling factor value is dependent on measurement, recording and data reduction procedures.