Using data from NASA's Magnetospheric Multiscale mission captured in a reconnection inflow on the magnetospheric side of Earth's dayside magnetopause, we find a region where the heat flux density gradient term balances the parallel compression term in the electron parallel temperature equation. Combining these observations with analysis of the generalized fluid equations indicates that such a behavior represents a quasi-isothermal region, where cold magnetosheath beams that have transported across the magnetopause introduce non-zero gradients in parallel heat flux density. This region should prevail near dayside reconnection X-lines in inflows on the magnetospheric side due to the formation of mixed electron distributions and increased parallel temperatures that arise from three-dimensional boundary dynamics.

中文翻译：

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磁层重联流入中平行电子温度的演变


使用来自美国宇航局磁层多尺度任务的数据，在地球日侧磁层顶的磁层流中捕获的再连接流入中，我们发现了一个区域，其中热通量密度梯度项平衡了电子平行温度方程中的平行压缩项。将这些观察结果与广义流体方程的分析相结合，表明这种行为代表了准等温区域，其中穿过磁层顶传输的冷磁束在平行热通量密度中引入了非零梯度。由于混合电子分布的形成和三维边界动力学引起的平行温度升高，该区域应该在磁层侧流入的日边再连接 X 线附近占主导地位。