Time–dependent occurrence rate of electromagnetic cyclotron waves in the solar wind: evidence for the effect of alpha particles?
Time–dependent occurrence rate of electromagnetic cyclotron waves in the solar wind: evidence for the effect of alpha particles?
复制标题
太阳风中电磁回旋波随时间变化的发生率：阿尔法粒子效应的证据？
DOI：
10.3847/2041-8213/aa88b3
复制
发表时间：
2017
影响因子：
7.9
通讯作者：
Huang J.
中科院分区：
文献类型：
--
作者：
Zhao G. Q.;Feng H. Q.;Wu D. J.;Chu Y. H.;Huang J.
Previous studies revealed that electromagnetic cyclotron waves (ECWs) near the proton cyclotron frequency exist widely in the solar wind, and the majority of ECWs are left-handed (LH) polarized waves. Using the magnetic field data from the STEREO mission, this Letter carries out a survey of ECWs over a long period of 7 years and calculates the occurrence rates of ECWs with different polarization senses. Results show that the occurrence rate is nearly a constant for the ECWs with right-handed polarization, but it varies significantly for the ECWs with LH polarization. Further investigation of plasma conditions reveals that the LH ECWs take place preferentially in a plasma characterized by higher temperature, lower density, and larger velocity. Some considerable correlations between the occurrence rate of LH ECWs and the properties of ambient plasmas are discussed. The present research may provide evidence for the effect of alpha particles on the generation of ECWs.
