OGO 5 observations of electrostatic turbulence in bow shock magnetic structures
OGO 5 observations of electrostatic turbulence in bow shock magnetic structures
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OGO 5 观测弓激磁结构中的静电湍流
DOI：
10.1029/ja075i019p03751
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发表时间：
1970
影响因子：
--
通讯作者：
C. Russell
中科院分区：
文献类型：
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作者：
R. W. Fredricks;G. Crook;C. Kennel;I. M. Green;F. Scarf;P. Coleman;C. Russell
我们目前的磁场，甚低频电场，和定向的正离子通量测量期间通过的OGO 5通过许多弓激波结构入境和出境于1968年3月12日。之所以选择这些冲击，是因为1968年3月11日至13日这段时间是相当安静的太阳风之一。这些数据在≥144 msec的时间尺度上进行了相关，并表明在激波阵面中，静电波湍流是由在尺度长度<$c/ωp−（电子惯性长度）上流动的反磁电流产生的。这种静电湍流在大跳跃的区域附近或区域内建立到高水平，|B|然后在下游迅速衰减。激增|B|并且质子的散射或随机化仅在达到强水平的静电湍流之后才被观察到;这导致静电湍流是冲击耗散过程的主要贡献者的结论。这种湍流最好解释为离子声或Buneman模式，由于双流不稳定性。显示了一个非常厚的激波结构，其中包含许多非常大的振幅和几乎可逆的磁场脉动。
We present magnetic field, VLF electric field, and directed positive ion flux measurements made during passage of OGO 5 through many bow shock structures both inbound and outbound on March 12, 1968. These shocks were chosen because the period March 11–13, 1968, was one of a reasonably quiet solar wind. The data are correlated on time scales ≥144 msec and show that electrostatic wave turbulence is generated in the shock front by diamagnetic currents flowing on scale lengths ∼c/ωp−, the electron inertial length. This electrostatic turbulence builds to high levels near or in the regions of large jumps in |B| and then decays rapidly downstream. A jump in |B| and the scattering or randomization of protons are observed to occur only after a strong level of electrostatic turbulence is achieved; this leads to the conclusion that the electrostatic turbulence is a major contributor to the shock dissipative process. This turbulence is best explained as the ion acoustic or Buneman mode due to two-stream instability. One very thick shock structure is displayed which contains many very large amplitude and nearly reversible magnetic field pulsations.