Physics
Scientific paper
May 2007
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2007jgra..11205314a&link_type=abstract
Journal of Geophysical Research, Volume 112, Issue A5, CiteID A05314
Physics
8
Ionosphere: Active Experiments, Ionosphere: Wave/Particle Interactions (7867), Ionosphere: Particle Acceleration, Ionosphere: Plasma Waves And Instabilities (2772)
Scientific paper
On 12 November 2001, the European Incoherent Scatter (EISCAT) high-frequency (HF) radio wave transmitter facility, operating in O-mode at 5.423 MHz with 550 MW effective radiated power, produced artificial optical rings which appeared immediately at transmitter turn-on and collapsed into blobs after ~60 s while descending in altitude. A similar descent in altitude was observed in the EISCAT ultra high frequency (UHF) ion line enhancements. Likewise, the stimulated electromagnetic emission (SEE) spectra changed as the pump frequency approached the fourth electron gyroharmonic due to pump-induced variations in electron concentration. Optical recordings were made from Skibotn at 630.0 and 557.7 nm and from Ramfjord in white light. The altitude of the initial optical ring and steady state blob has been estimated by triangulation. The evolution in altitude of the optical emissions, ion line enhancements, and SEE spectra all show a similar morphology but are generally not at exactly the same height. Typically, the optical height is close to and a few kilometers below that of the radar backscatter but sometimes above it, both of which are above the SEE generation altitude. There is evidence that upper hybrid (UH) waves, which propagate perpendicular to the magnetic field line, and Langmuir (L) waves, which propagate parallel to the magnetic field line, act simultaneously to accelerate electrons even in the steady state.
Ashrafi Mina
Isham B.
Kaila K.
Kosch Michael J.
No associations
LandOfFree
Spatiotemporal evolution of radio wave pump-induced ionospheric phenomena near the fourth electron gyroharmonic 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 Spatiotemporal evolution of radio wave pump-induced ionospheric phenomena near the fourth electron gyroharmonic, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Spatiotemporal evolution of radio wave pump-induced ionospheric phenomena near the fourth electron gyroharmonic will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-770673