Radar observations of two‐dimensional turbulence in the equatorial electrojet, 2

Abstract

Observations with an altitude resolution of about 1 km were made with the large, vertically directed 50‐MHz radar system at the Jicamarca Radar Observatory during the day, when the electrojet was strong. Type 1 (‘two stream’) echoes were seen in a limited range of altitudes, with Doppler shifts corresponding to upward and downward motion at the acoustic velocity. Most of the radar returns were due to type 2 echoes, however. The direction of motion of the type 1 waves sometimes reversed in as little as 1 s, supporting a turbulent model of the electrojet region. During the day the upgoing type 1 waves were observed to be somewhat more easily excited than the downgoing waves, an effect similar to an east‐west asymmetry noted in earlier studies. The correspondence between the Jicamarca radar observations and rocket measurements in India is discussed.