The energy transfer between ions (protons) and low frequency waves (LFWs) in the frequency range f1 from 0.3 to 10 Hz is observed by Cluster crossing the high-altitude polar cusp. The energy transfer between low f...The energy transfer between ions (protons) and low frequency waves (LFWs) in the frequency range f1 from 0.3 to 10 Hz is observed by Cluster crossing the high-altitude polar cusp. The energy transfer between low frequency waves and ions has two means. One is that the energy is transferred from low frequency waves to ions and ions energy increases, The other is that the energy is transferred from ions to low frequency waves and the ion energy decreases. lon gyratory motion plays an important role in the energy transfer processes. The electromagnetic field of f1 LFWs can accelerate or decelerate protons along the direction of ambient magnetic field and warm or refrigerate protons in the parallel and perpendicular directions of ambient magnetic field, The peak values of proton number densities have the corresponding peak values of electromagnetic energy of low-frequency waves. This implies that the kinetic Alfven waves and solitary kinetic Alfven waves possibly exist in the high-altitude cusp region.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 40390150, and the Postdoctoral Science Foundation of High Education of China.
文摘The energy transfer between ions (protons) and low frequency waves (LFWs) in the frequency range f1 from 0.3 to 10 Hz is observed by Cluster crossing the high-altitude polar cusp. The energy transfer between low frequency waves and ions has two means. One is that the energy is transferred from low frequency waves to ions and ions energy increases, The other is that the energy is transferred from ions to low frequency waves and the ion energy decreases. lon gyratory motion plays an important role in the energy transfer processes. The electromagnetic field of f1 LFWs can accelerate or decelerate protons along the direction of ambient magnetic field and warm or refrigerate protons in the parallel and perpendicular directions of ambient magnetic field, The peak values of proton number densities have the corresponding peak values of electromagnetic energy of low-frequency waves. This implies that the kinetic Alfven waves and solitary kinetic Alfven waves possibly exist in the high-altitude cusp region.
基金The authors are grateful to Japanese WDC-C2 KY0T0 AE index service for presenting AU,AL and AE indices and to Goddard Space Flight Center,NASA for presenting data of the interpanaetary condition and auroradata.Thanks are also given to Cluster and Double-Star Data Center for providing data used in the study.This work was supported by the National Natural Science Foundation of China(Grant No.40390152)the State Key Basic Research Program(Grant No.G200000784)the XK100010404 of Beijing City,and the Space Weather Laboratory,Center for Space Science and Applied Research,CAS.