An analysis of vertical scale structure and wind shear in the mesosphere from falling sphere data

Small-scale features in four wind profiles obtained from falling sphere measurements at Ascension Island are examined with respect to wave structure in the altitude interval from 50 to 65 km, a region of temperature lapse with height. An objective method of defining the predominant wavelength in the profiles in this altitude interval is presented, and it is found that for all profiles the defined length in the component transverse to the mean motion exceeds that of the component along the mean motion. Corresponding wind shear values show no similar component difference. The vertical scale of the observed features appears to be independent of the underlying surface relief.