AI 中文总结
研究日球电流片中嵌入的离子尺度电流片及其与重联喷流边缘流动剪切层的关系，通过分析帕克太阳探测器观测数据，识别出多种类型的离子尺度电流片，揭示了重联喷流剪切层在多尺度结构形成中的作用。
AI 中文摘要
背景。日球电流片（HCS）中的磁重联在重构太阳风磁拓扑结构以及产生等离子体喷流和磁岛方面起着重要作用。虽然许多观测研究报道了HCS重联的大规模特征，但重联区域内的动力学尺度结构仍不太清楚。目的。我们研究嵌入HCS重联区域的离子尺度电流片（CSs）及其与重联喷流边缘流动剪切层的关系。方法。我们使用高时间分辨率磁场测量分析了帕克太阳探测器在2024年3月29日观测到的一次HCS穿越。我们关注重联喷流边缘流动剪切层两个短时间间隔内的离子尺度磁转变，并在局部LMN坐标系中对其进行研究。结果。识别出12个代表性的CSs，其持续时间平均约为0.06秒，对应空间尺度仅为几个离子惯性长度。根据平面外磁分量$B_{M}$的行为将它们分为三种类型：（1）在重联场（$B_{L}$）中显示清晰双极$B_{M}$变化且无分叉的CSs；（2）具有双极$B_{M}$变化和以平台结构为特征的分叉$B_{L}$剖面的CSs；（3）强波动掩盖了原本预期的双极特征的CSs。结论。HCS中的重联喷流剪切层可能是承载一系列离子尺度CSs的活跃位点。这为重联的多尺度结构提供了新见解，并表明流动剪切层可能在产生次级动力学尺度结构中起重要作用。
英文摘要
Context. Magnetic reconnection in the heliospheric current sheet (HCS) plays an important role in restructuring the solar wind magnetic topology and generating plasma jets and magnetic islands. While large-scale signatures of HCS reconnection have been reported in many observational studies, the kinetic-scale structure embedded within reconnection regions remains less well understood. Aims. We investigate the ion-scale currents sheets (CSs) embedded within an HCS reconnection region and their relationship to the flow-shear layer at the edge of a reconnection jet. Methods. We analyzed an HCS crossing observed by the Parker Solar Probe on March 29, 2024, using high-time-resolution magnetic field measurements. We focused on ion-scale magnetic transitions within two brief intervals of flow-shear layer at the edges of the reconnection jet and examined them in a local LMN coordinate system. Results. Twelve representative CSs are identified, whose duration is on average $\sim$0.06 sec, corresponding to spatial scales of only a few ion inertial lengths. They are classified into three types based on the behavior of the out-of-plane magnetic component $B_{M}$: (1) CSs showing clear bipolar $B_{M}$ variations without bifurcation in reconnecting-field ($B_{L}$), (2) CSs with both bipolar $B_{M}$ variations and bifurcated $B_{L}$ profiles characterized by a plateau structure, and (3) CSs where strong fluctuations obscure an otherwise expected bipolar signature. Conclusions. The reconnection jet shear layer in the HCS may serve as an active site that hosts a chain of ion-scale CSs. This provides new insight into the multiscale structure of HCS reconnection and suggests that flow shear layers may play an important role in generating secondary kinetic-scale structures.
Comments9 pages, 11 figures, submitted to A&A
