Other
Scientific paper
Mar 2003
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2003angeo..21..761m&link_type=abstract
Annales Geophysicae, vol. 21, Issue 3, pp.761-777
Other
8
Scientific paper
Multi-frequency observations of E-region coherent backscatter from decametre waves reveal that auroral echoes tend to comprise two spectral components superimposed, one at low Doppler shifts, below 250 ms-1, and the other Doppler shifted to near the ion-acoustic speed or above, up to 800 ms-1. The low Doppler shift component occurs at all look directions; Doppler shifts near the ion acoustic speed occur when looking at low flow angles along the direction of the electron drift in the electrojet, and Doppler shifts in excess of the ion acoustic speed occur at intermediate flow angles. The latter population appears most commonly at radar frequencies near 10 12 MHz, with its occurrence decreasing dramatically at higher frequencies. The velocity of the high Doppler shift echoes increases with increasing radar frequency, or irregularity wave number k. The velocity of the low Doppler shift population appears to be suppressed significantly below the line-of-sight component of the electron drift. Initial estimates of the altitude from which scatter occurs suggest that the high Doppler shift echoes originate from higher in the E-region than the low Doppler shift echoes, certainly in the eastward electrojet. We discuss these observations with reference to the theories of de/stabilization of two-stream waves by electron density gradients and electrostatic ion cyclotron waves excited by field-parallel electron drifts.
Lester Mark
Milan Stephen E.
Sato Naoko
No associations
LandOfFree
Multi-frequency observations of E-region HF radar aurora does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Multi-frequency observations of E-region HF radar aurora, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Multi-frequency observations of E-region HF radar aurora will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1881677