Experimental evidence for direct penetration of ULF waves from the solar wind and their possible effect on acceleration of radiation belt electrons |
| |
| Authors: | A S Potapov T N Polyushkina |
| |
| Institution: | 1.Institute of Solar-Terrestrial Physics, Siberian Branch,Russian Academy of Sciences,Irkutsk,Russia |
| |
| Abstract: | The event of March 12–19, 2009, when a moderately high-speed solar wind stream flew around the Earth’s magnetosphere and carried
millihertz ultralow-frequency (ULF) waves, has been analyzed. The stream caused a weak magnetic storm (D
st min = −28 nT). Since March 13, fluxes of energetic (up to relativistic) electrons started increasing in the magnetosphere. Comparison
of the spectra of ULF oscillations observed in the solar wind and magnetosphere and on the Earth’s surface indicated that
a stable common spectral peak was present at frequencies of 3–4 mHz. This fact is interpreted as evidence that waves penetrated
directly from the solar wind into the magnetosphere. Possible scenarios describing the participation of oscillations in the
acceleration of medium-energy (E > 0.6 MeV) and high-energy (E > 2.0 MeV) electrons in the radiation belt are discussed. Based on comparing the event with the moderate magnetic storm of
January 21–22, 2005, we concluded that favorable conditions for analyzing the interaction between the solar wind and the magnetosphere
are formed during a deep minimum of solar activity. |
| |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ |
|
