Date of Award

Spring 1996

Project Type


Program or Major


Degree Name

Doctor of Philosophy

First Advisor

Roy Torbert


Measurements of the ion distribution function, electron density, wave activity, and convection electric field have been made in situ by a sounding rocket flown through the artificially heated F layer ionosphere over Arecibo, Puerto Rico. The ion distributions show the effect of the HF heater through elevated effective temperatures, superthermal fluctuation level, and a plume-like population of energetic ions drifting out of the HF reflection region. The electron density, from a Langmuir probe, shows meter-scale depletions of $\sim$10% in the immediate vicinity of the reflection height, both above and below (Kelley et al., 1995). A shear in the convection electric field observed at the reflection layer can be interpreted as the return current at the westward edge of a heater driven current system.

The payload also passed within 2.2 km of the Arecibo 430 MHz incoherent scatter radar (ISR) beam, where a burst of energetic ions was observed, preceded by coherent wave activity in both the Langmuir and electric field double-probe. A cross spectral analysis indicates that the waves originate from the ISR beam.