UPPER ATMOSPHERE WINDS MEASURED BY GUN-LAUNCHED PROJECTILES.

Abstract : The High Altitude Research Project (HARP) uses gun-launched projectiles to probe the upper atmosphere. Under this project, 5-inch projectiles have reached 70 km, and 16-inch projectiles have attained an altitude of 143 km over Barbados, West Indies. The first experimental program for the 16-inch gun has been the production of luminous tri-methyl aluminum (TMA) trails for the measurement of winds above 90 km. In the period July 1964 to February 1966, 49 such nightime trails were photographed and 29 of these trails have been analyzed. During 42 of these flights, concurrent ionosonde records were taken and the locations of sporadic E layers have been determined for comparison with the wind profiles. The wind data analyzed showed little evidence for the Rosenberg rotating wind vector model, but on nine trails direction reversals occuring in less than 3 km of vertical displacement were observed. Layers of constant direction flow with thicknesses greater than 8 km were observed on 14 trails, and a maximum wind speed of 147 m/sec was measured. The six trails of the night of 20 - 21 September showed a rapid variation of N - S component of wind at fixed altitude with peak-to-peak amplitude of over 200 m/sec. Sine waves were fitted to wind components at fixed altitude with fair to good standard deviations. (Author)