Observations of the HF-enhanced plasma line with a 46.8MHz radar and reinterpretation of previous observations with the 430 MHZ radar

Fejer, J.A.; Ierkic, H.M.; Woodman Pollitt, Ronald Francisco; Röttger, J.; Sulzer, M.; Behnke, R.A.; Veldhuis, A.

Observations of the HF-enhanced plasma line with a 46.8MHz radar and reinterpretation of previous observations with the 430 MHZ radar

Abstract

During 5.1 MHz HF transmissions below the F-region penetration frequency by a nearby ionospheric modification facility, radar echoes coming from F-region heights at a frequency of 46.8 + 5.1 = 51.9 MHz were received while a VHF radar using the 305 m spherical reflector at Arecibo was transmitting pulses coherently on 46.8 MHz. The bandwidth of the echoes was less than 10 Hz. The so-called decay line due to the parametric decay instability was expected at a frequency lower by about 300 Hz but it was not observed. Density variations caused by the ponderomotive force resulting from the standing wave pattern at 5. 1 MHz were tentatively invoked to explain the observations. Poorly understood aspects of previous analogous observations with the 430 MHz radar can be similarly explained.

Date

1982

Keywords

Radar , Ionosphere , Echoes , Plasma

Citation

Fejer, J. A., Ierkic, H. M., Woodman, R. F., Röttger, J., Sulzer, M., Behnke, R. A., & Veldhuis, A. (1982). Observations of the HF-enhanced plasma line with a 46.8MHz radar and reinterpretation of previous observations with the 430 MHZ radar. Journal of Geophysical Research: Space Physics, 88 (A3), 2083-2092. https://doi.org/10.1029/JA088iA03p02083