and 3 are observed. In Fig. 4, the peak-to-mean ratios for unstableconditions start at higher values near the source compared to Fig. 3,and their decrease with distance is much reduced, leading to peakto-mean ratios at 100mbetween 5 and 8 (Fig. 4, left panel) or 4 and5 (Fig. 4, right panel). From Fig. 3, a peak-to-mean ratio of only 1 isobtained at 100 m in unstable conditions. In Fig. 4, the attenuationcurves in unstable conditions deliver values above 1 several 100 mdownwind. For neutral and stable conditions, the differences betweenthe curves in Fig. 3 and those in Fig. 4 are far less pronounced,but the peak-to-mean ratios still decrease less than inFig. 3. From less than 200monwards, the factor 4 of the German TALuft (2002) is larger than any of the peak-to-mean ratios from ultrasonicanemometer data for these distances