High-resolution radar observations of daytime kilometer-scale wave structure in the equatorial electrojet
- Cornell Univ., Ithaca, NY (United States)
- Columbia Univ., New York, NY (United States)
Using a new antenna configuration and new data processing hardware, the authors probed the electrojet with unprecedented spatial resolution in January 1991 at Jicamarca. The altitude resolution was 125 m, and the east-west antenna beamwidth was about 0.6[degrees], or about 1 km at electrojet altitudes. The high spatial resolution allowed them to observe, at certain altitudes and times, pronounced wavelike structures with vertical wavelengths of the order of 1 km and periods of tens of seconds. These observations closely resemble the predictions of recent nonlocal, nonlinear numerical simulations of large-scale turbulence in the equatorial electrojet. The comparison demonstrated the validity of the theory and confirmed the idea that the Doppler power spectra of type 2 echoes at 50 MHz (due to 3-m plasma waves generated by the gradient-drift instability and a nonlinear cascade of energy from long-wavelength modes to short) are controlled primarily by the large-scale dynamics and not by the nonlinear local growth and decay rates of the 3-m waves themselves. 16 refs., 7 figs.
- OSTI ID:
- 6711546
- Journal Information:
- Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 99:A1; ISSN JGREA2; ISSN 0148-0227
- Country of Publication:
- United States
- Language:
- English
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