Magnetic clouds are large-scale transient structures in the solar wind with low plasma- β , low-amplitude magnetic field fluctuations, and twisted field lines with both ends often connected to the Sun. Their inertial-range turbulent properties have not been examined in detail. In this Letter, we analyze the normalized cross helicity, σ c , and residual energy, σ r , of plasma fluctuations in the 2018 November magnetic cloud observed at 0.25 au by the Parker Solar Probe. A low value of ##IMG## [http://ej.iop.org/images/2041-8205/900/2/L32/apjlabb021ieqn1.gif] {$| {\sigma }_{c}| $} was present in the cloud core, indicating that wave power parallel and antiparallel to the mean field was approximately balanced, while the cloud’s outer layers displayed larger amplitude Alfvénic fluctuations with high ##IMG## [http://ej.iop.org/images/2041-8205/900/2/L32/apjlabb021i...] {$| {\sigma }_{c}| $}

中文翻译：

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派克太阳探测器观测到的2018年11月磁云的交叉螺旋

磁云是太阳风中的大规模瞬态结构，具有低等离子-β，低振幅磁场波动和扭曲的磁力线，其两端通常连接到太阳。他们的惯性范围湍流特性尚未详细检查。在这封信中，我们分析了派克太阳探测器在0.25 au观测到的2018年11月磁云中的等离子体波动的归一化交叉螺旋度σc和残余能量σr。## IMG ##的低值[http://ej.iop.org/images/2041-8205/900/2/L32/apjlabb021ieqn1.gif] {$ | {\ sigma} _ {c} | $}存在于云核心中，这表明与平均场平行和反平行的波功率是近似平衡的，而云的外层则显示出较大的Alfvénic波动幅度，并具有较高的## IMG ## [http：//ej.iop。org / images / 2041-8205 / 900/2 / L32 / apjlabb021i ...] {$ | {\ sigma} _ {c} | $}