The low-latitude boundary layer (LLBL) is a crucial region for the transfer of mass, momentum, and energy between the solar wind and the planetary magnetosphere. However, the processes of energy conversion within this layer are not well understood. In this study, the anomalous magnetic topology sublayers (AMTSs) within Earth's inner LLBL are investigated during the local reconnection inactive period, using data from the Magnetospheric Multiscale (MMS) mission. We present the first in situ observations showing that these AMTSs lead to significant energy conversion within the inner LLBL. The electron populations in AMTSs are dominated by either the magnetospheric or magnetosheath populations, creating a substantial electron temperature gradient between these sublayers. This temperature gradient, in turn, generates non-ideal electric fields through the pressure gradient term. Our findings improve the understanding of dynamics in the planetary LLBL, highlighting the importance of AMTSs in the energy conversion process.

中文翻译：

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与内部低纬度边界层中异常磁拓扑子层相关的能量转换


低纬度边界层 （LLBL） 是太阳风和行星磁层之间质量、动量和能量传递的关键区域。然而，该层内的能量转换过程尚不清楚。在这项研究中，使用来自磁层多尺度 （MMS） 任务的数据，在本地重新连接非活动期间研究了地球内部 LLBL 内的异常磁拓扑子层 （AMTS）。我们提出了第一个原位观察结果，表明这些 AMTS 导致内部 LLBL 内显着的能量转换。AMTS 中的电子群以磁层或磁层群为主，在这些子层之间产生了很大的电子温度梯度。反过来，这种温度梯度会通过压力梯度项产生非理想电场。我们的研究结果提高了对行星 LLBL 动力学的理解，突出了 AMTS 在能量转换过程中的重要性。