资源环境科技发展态势分析平台

During whistler wave excitation, electron energy is transferred from electrons to waves. There is little observational evidence that such a process operates effectively in the magnetotail, however. Using a large observational database from the Time History of Events and Macroscale Interactions during Substorms mission, we investigate whistler wave excitation within and around dipolarizing flux bundles (DFBs), critical energy transporters in the magnetotail, and the evacuation of perpendicular electron energy by whistler wave Poynting flux. We find that perpendicular anisotropy of suprathermal (similar to 10 keV) electrons is the major free energy source for whistler wave excitation near DFBs. During earthward transport of electrons by DFBs, 3.7% of the suprathermal electron energy flux is evacuated in the form of whistler wave Poynting flux. This suggests that whistler waves play an important role in electron thermodynamics in the magnetotail by significantly modifying the otherwise adiabatically shaped electron distributions.