Physics
Scientific paper
Dec 2001
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2001agufmsm52a..08k&link_type=abstract
American Geophysical Union, Fall Meeting 2001, abstract #SM52A-08
Physics
2720 Energetic Particles, Trapped, 2730 Magnetosphere: Inner, 2788 Storms And Substorms, 6939 Magnetospheric Physics, 6964 Radio Wave Propagation
Scientific paper
Drastic changes of relativistic electron population in the outer radiation belt during magnetic storms have been observed for many years. The relativistic electron flux decreases during the main phase of the storm and increases to the prestorm level during the recovery phase. One of the plausible mechanisms of the relativistic electron enhancement is the wave-particle resonant diffusion by whistler mode chorus. In the present paper, we introduce chorus emissions observed by the Akebono satellite in the vicinity of the outer radiation belt associated with magnetic storms. Akebono was launched in 1989 with an altitude range between 300km and 10,000km, and has been operated successfully for about 12 years. Using the long period observation datasets of VLF plasma waves obtained by Akebono, we statistically investigated the time variation and spatial distribution of VLF waves in the outer radiation belt. Our statistical study clarified that the wave above 1kHz in the vicinity of the outer radiation belt is dominantly chorus emission. The wave intensity is enhanced during the recovery phase of magnetic storms. The distribution region of the chorus during the recovery phase of the magnetic storm is firstly located around the inner edge of the outer radiation belt, and gradually shifts toward the outer L-shell region. It is also found that the most intense chorus is observed in the noon sector and higher frequency part of chorus tends to be distributed along smaller L-value and in earlier local time sector. Using the five components of wave data obtained by Akebono, direction finding of the chorus was performed. It is found that the chorus basically propagates toward the lower altitude region from the equatorial region along the geomagnetic field line with a large wave normal angle. The statistical study on time variation and spatial distribution of the chorus in the outer radiation belt together with the direction finding analysis enables us to estimate the total energy of the chorus generated during the storm-recovery. It is a quite important clue to discuss the energy transfer process from chorus to the relativistic electrons. Acknowledgments: The authors wish to thank I. Nagano and the other Akebono/VLF members for their contribution to the VLF instrument and its data analyses. We also acknowledge K. Tsuruda, T. Mukai and the other Akebono mission project members for their support.
Goto Yasuhiro
Kasahara Yasushi
Miyoshi Yasunobu
Obara Takahiro
Uchiyama Hideki
No associations
LandOfFree
Time Variation and Spatial Distribution of Chorus Emissions in the Outer Radiation Belt during Magnetic Storm 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 Time Variation and Spatial Distribution of Chorus Emissions in the Outer Radiation Belt during Magnetic Storm, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Time Variation and Spatial Distribution of Chorus Emissions in the Outer Radiation Belt during Magnetic Storm will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1386287