Meteoric Echo Study of Upper Atmosphere Winds

A method is developed for measuring the velocity of winds in the 90- to 110-kilometer height region of the upper atmosphere. From the Doppler frequency shift imparted to a continuous-wave reflection from a meteoric ionization column, a measure of the wind drift of the trail is found. Statistical analysis enables average wind velocities to be measured to within perhaps 20 per cent, and direction to 20°, in a period of one or two hours. Observations made during the early morning hours in the summer of 1949 show typical average wind velocities to be 125 kilometers per hour, with motions from south-southwest and north the most common. On some occasions, evidence of a nonuniform wind structure is found.