Physics
Scientific paper
Aug 2002
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2002jgra..107.1204h&link_type=abstract
Journal of Geophysical Research (Space Physics), Volume 107, Issue A8, pp. SIA 21-1, CiteID 1204, DOI 10.1029/2001JA900144
Physics
4
Ionosphere: Plasma Waves And Instabilities, Ionosphere: Wave/Particle Interactions, Magnetospheric Physics: Auroral Phenomena (2407), Magnetospheric Physics: Electric Fields (2411)
Scientific paper
We present a comprehensive overview of the electron density and six different wave types in the range ~1 Hz to ~1 MHz, and we investigate their occurrence, average wave frequency and amplitude as a function of location, Kp index, and solar illumination. Twenty-one months of Freja observations from the Northern Hemisphere obtained at ~1700 km altitude and invariant latitudes 40°-75° are used. We find that waves around the lower hybrid frequency occur in one low-latitude dayside band and one high-latitude nightside band. The latter band correlates with precipitating auroral electrons and coexists with electromagnetic ion cyclotron (EMIC) waves. This indicates the importance of energetic electrons for the wave generation. Both broadband ELF waves and broadband high-frequency whistler mode waves are found at high latitudes, but whistler mode emissions are most common in regions of high electron densities on the dayside, while broadband ELF waves are found where the density is reduced on the nightside. Moreover, the average density in the presence of broadband ELF waves is more reduced when the ionosphere is dark than when it is sunlit. However, broadband whistler mode waves, Langmuir waves, and waves with an upper cutoff just below the proton gyrofrequency coincide with density enhancements when the ionosphere is dark. Ion heating correlated with auroral electrons coexists with EMIC waves and the high-latitude band of waves around the lower hybrid frequency. Furthermore, ion heating not correlated with downgoing electrons coexists with broadband ELF waves.
André Martial
Eriksson Anders I.
Hamrin Maria
Norqvist Patrik
No associations
LandOfFree
A statistical study of wave properties and electron density at 1700 km in the auroral region 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 A statistical study of wave properties and electron density at 1700 km in the auroral region, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A statistical study of wave properties and electron density at 1700 km in the auroral region will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-927949