PARALLEL ELECTRIC FIELD SPECTRUM OF SOLAR WIND TURBULENCE
PARALLEL ELECTRIC FIELD SPECTRUM OF SOLAR WIND TURBULENCE
复制标题
太阳风湍流的平行电场谱
DOI：
10.1088/2041-8205/768/1/l10
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
C. H. Chen
中科院分区：
文献类型：
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作者：
F. Mozer;C. H. Chen
通过检索10多个卫星年的THEMIS和Cluster数据，找到了3个未受干扰的太阳风中平行电场湍流的可靠例子。这些例子中的垂直和平行电场谱具有相似的形状和幅度，即使在大尺度（低于离子陀螺尺度的频率）下也是如此，其中没有平行电场分量的阿尔芬湍流被认为占主导地位。平行电场波动的频谱是幂律，其指数在离子尺度（∼0.1 Hz）以下接近-5/3，并且在该频率附近频谱平坦。在小尺度（高于几赫兹）下，光谱比 -5/3 更陡，值在 -2.1 到 -2.8 范围内。这些更陡的斜率与阿尔芬湍流的预期一致，尽管它们相对于垂直波动的幅度大于预期。
By searching through more than 10 satellite years of THEMIS and Cluster data, 3 reliable examples of parallel electric field turbulence in the undisturbed solar wind have been found. The perpendicular and parallel electric field spectra in these examples have similar shapes and amplitudes, even at large scales (frequencies below the ion gyroscale), where Alfvénic turbulence with no parallel electric field component is thought to dominate. The spectra of the parallel electric field fluctuations are power laws with exponents near −5/3 below the ion scales (∼0.1 Hz), and with a flattening of the spectrum in the vicinity of this frequency. At small scales (above a few Hz), the spectra are steeper than −5/3 with values in the range of −2.1 to −2.8. These steeper slopes are consistent with expectations for kinetic Alfvén turbulence, although their amplitude relative to the perpendicular fluctuations is larger than expected.