Radar studies of the equatorial electrojet at three frequencies

摘要: Radar measurements at 16.25, 49.92, and 146.25 MHz of electrojet irregularities Jicamarca indicate that (1) the plasma-wave velocities observed for type I (two-stream) are approximately proportional with ratios 0.9:1.0:1.1; (2) these can vary throughout day by as much 50%; (3) mean II equal 16 50 MHz; (4) strength decreases more rapidly wavelength than I, a result signal predominates MHz, but only is 146 (5) dependence scattering cross section on pronounced probably because different character signals. On basis other observations, we conclude Doppler velocity echoes corresponds to acoustic rather electron streaming velocity, contrary prediction linear theory; varies in least approximate agreement radar not excited directly, from nonlinear interactions among larger irregularities.