Radar observations of two-dimensional turbulence in the equatorial electrojet

Radar studies at 50 MHz of irregularities in the electrojet have been made at the Jicamarca Observatory with much better spatial and temporal resolution than that in the past. The Doppler spectra of the signals reveal a complicated and rapidly varying structure, which was masked by the crude resolution of earlier measurements. The present results strongly support the idea that the small-scale irregularities observed by the radar are generated by a two-dimensional coupling process in which large-scale irregularities, generated by the gradient drift plasma instability, in turn generate small irregularities traveling in other directions via either the gradient drift or the two-stream instability.