A series of 18 mesospheric wind profiles with an altitude resolution of about 50 m has been obtained by means of radar tracking of chaff clouds. The experiments were performed during wintertime at 69¿N latitude and they cover mostly the 72 to 86 km altitude range. The observed wind shears frequently concentrate the changes of wind direction &agr; with altitude z into shallow layers, which we designate ''wind corners.'' They are characterized by having large directional gradients d&agr;/dz (>5¿/100 m) and by having a small vertical extent (≤500 m). Also wind corners separate altitude layers of a few km thickness in which little change of wind direction occurs. Frequently wind corners coincide with local minima in the horizontal wind speed (≤15 m/s).