Polarization properties of low frequency electromagnetic cyclotron waves associated with magnetic clouds
Polarization properties of low frequency electromagnetic cyclotron waves associated with magnetic clouds
复制标题
与磁云相关的低频电磁回旋波的偏振特性
DOI：
10.1007/s10509-018-3271-8
复制
发表时间：
2018
期刊：
影响因子：
--
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.;Huang J.
最近的研究表明，在行星际空间常见的磁性结构磁云（MCs）内部和周围存在大量的低频电磁回旋波（ECWs）。利用STEREO航天器的磁场数据，研究了与120个mc相关的ECWs的极化特性。结果表明，ECWs是高度横向、强极化、椭圆度大的波。具体来说，几乎所有的波都发生在横向功率与总功率之比大于0.94、极化度大于0.85、椭圆度大于0.5的情况下。这些量的平均值分别可达0.99、0.96、0.85。特别是，对于具有左极化的ECWs，其椭圆率随波法向角的变化有减小的趋势。这种下降趋势与最近的理论和模拟结果一致。
Recent studies have revealed that there are a large number of low frequency electromagnetic cyclotron waves (ECWs) occurring in and around magnetic clouds (MCs) that are common magnetic structures in interplanetary space. Using magnetic field data from the STEREO spacecraft, this paper investigates polarization properties of ECWs associated with 120 MCs. Results show that the ECWs are highly transverse, strongly polarized waves with large ellipticities. Specifically, almost all of the waves take place with the ratios of transverse power to total power higher than 0.94, polarization degrees greater than 0.85, and ellipticities larger than 0.5. The mean values of these quantities can be up to 0.99, 0.96, 0.85, respectively. In particular, there is a tendency of ellipticities decreasing with respect to the wave normal angles for ECWs with left handed polarization. The decreasing tendency is consistent with the recent theory and simulation results.