Investigation of Outer Length Scale In Optical Turbulence Using an Acoustic Sounder

摘要

The horizontal separations between convective thermal plumes, and features within a thermal plume, were determined through the use of an acoustic sounder, an anemometer and extensive data analysis. The mean, standard deviation, median and mode were calculated for the computed correlation lengths of the acoustic sounder data sampled in time intervals of 2, 5 and 10 minutes. The data sampled at 2 and 5-minute intervals emphasized features within an individual thermal plume. The mean correlation distances found for 2 and 5- minute intervals were 81 meters 70 meters and 89 meters 72 meters, respectively. Their medians were 61 meters and 69 meters; and their modes were 41 meters and 50 meters, respectively. The 10-minute time interval statistics used a low pass filter to emphasize larger scale features. The mean correlation length was 494 meters 373 meters, the median was 391 meters and the mode was 316 meters. These distances represent the distance between the center of a plume and the center of a quiet region adjacent to that plume.