MU Radar observations of kilometer‐scale waves in the midlatitude lower E‐region

摘要: The multi-beam high resolution MU radar experiments, conducted in February 2000, revealed for the first time kilometer-scale waves lower E-region over Shigaraki, Japan. waves, occurring a narrow height range of 92-97 km, have vertical wavelengths 0.6 to 1.2 km and periods 30 90 s. signal intensities associated with these signal-to-noise ratio values less than ∼5 dB, are by about 20 dB compared that quasi-periodic echoes at higher heights. occur both negative positive rates, changing systematically from one other −25 m s−1and s−1, respectively. Doppler velocities, ranging −50 25 generally same sense as but somewhat greater magnitude. periodicity wavelength seem resemble those equatorial electrojet Jicamarca observations also nonlocal nonlinear simulations gradient-drift instability. Behavior however, is found be different reported region.