JICAMARCA RADAR MEASUREMENTS OF WINDS AND TURBULENCE IN THE STRATOSPHERE
FLEISCH, DANIEL ALFRED
Doctor of Philosophy thesis
A series of 48-hour experiments performed quarterly in 1977 to study radar returns from the lower stratosphere is described. Current theories of stratospheric scatter of radio waves are presented and the radar equation pertinent to the large array at Jicamarca, Peru is derived. Observational and data reduction techniques are discussed. Experimental results concerning scattered power, mean wind velocities and velocity fluctuations are presented. It is found that isotropic turbulent scatter is not the only scattering mechanism operating in the stratosphere, and modifications to the radar equation which arise from turbulent rolls or thin layers of refractive index variation are needed. Mean winds measured by radar are comparable to those determined by rawinsonde ascent. Velocity oscillations of approximately 5-minute periods are interpreted as buoyancy oscillations with 2 km horizontal wavelength and phase velocity of 6 m/s. Tidal oscillations with periods of 24 and 12 hours are also observed. Suggestions for future measurements at Jicamarca and other institutions are offered.
Physics, Atmospheric Science