Ionospheric turbulence: case studies in equatorial spread F and development of a rocket-borne interferometer

In March, 1983, two rockets were launched into the disturbed nighttime equatorial F-region from Punta Lobos, Peru. The plasma density measurements from these flights confirm that the topside spread F plumes identifiable in the backscatter power maps produced at the nearby Jicamarca Radar Observatory are correlated with large scale (∼20 km) density depletions. The downward gradients of these depletions are highly structured, consistent with the linear theory of the gravitational instability. The wavenumber spectrum associated with these density irregularities occasionally exhibits a k/sup -1.5/ form for wavelengths longer than about one kilometer, as reported previously by Rina et al. [1981]. These observations are shown to be consistent with the nonlinear theory of Sudan and Keskinen [1984], although they also may be explained by at least two linear mechanisms: the generation of turbulence on the steepened walls of spread F bubbles, and the nonlocal role of the E-region in the development of spread F