论文标题

在时代磁性磁性时通量转移事件的体积研究

A Volumetric Study of Flux Transfer Events at the Dayside Magnetopause

论文作者

Paul, Arghyadeep, Vaidya, Bhargav, Strugarek, Antoine

论文摘要

日期磁粘着的局部磁重新连接导致磁通转移事件(FTES)的产生。 FTE中的磁场表现出复杂的螺旋通量旋转拓扑。利用自适应网状细化(AMR)策略,我们对类似地球的行星的磁层进行了三维磁流体动力学模拟,并研究了这些FTES的演变。我们第一次在3D中检测并跟踪FTE结构,并呈现FTE进化的完整体积图片。 FTE体积内热力学量的时间演变证实,连续重新连接确实是主动FTE生长的主要原因,如P-V曲线偏离绝热曲线所表明的那样。对FTE的磁性特性的研究表明,FTE体积内垂直电流的迅速下降,表现出内部电流倾向于被对齐的趋势。对这种FTE的无线磁通绳模型的有效性的评估表明,结构向恒定$α$状态漂移,但连续重新连接抑制了达到纯无线性无线构型的实现。另外,将所选FTE所包含的通量计算为在0.3-1.5 MWB之间。通量含量最高的FTE构成了$ \ sim $ 1%的净日期开放通量。将这些通量值与无线电通量循环模型提供的估计值进行比较。对于选定的FTE,由于连续重新连接的通量注入,无线性力模型低估了通量含量高达40%。

Localized magnetic reconnection at the dayside magnetopause leads to the production of Flux Transfer Events (FTEs). The magnetic field within the FTEs exhibit complex helical flux-rope topologies. Leveraging the Adaptive Mesh Refinement (AMR) strategy, we perform a 3-dimensional magnetohydrodynamic simulation of the magnetosphere of an Earth-like planet and study the evolution of these FTEs. For the first time, we detect and track the FTE structures in 3D and present a complete volumetric picture of FTE evolution. The temporal evolution of thermodynamic quantities within the FTE volumes confirm that continuous reconnection is indeed the dominant cause of active FTE growth as indicated by the deviation of the P-V curves from an adiabatic profile. An investigation into the magnetic properties of the FTEs show a rapid decrease in the perpendicular currents within the FTE volume exhibiting the tendency of internal currents toward being field aligned. An assessment on the validity of the linear force-free flux rope model for such FTEs show that the structures drift towards a constant-$α$ state but continuous reconnection inhibits the attainment of a purely linear force-free configuration. Additionally, the flux enclosed by the selected FTEs are computed to range between 0.3-1.5 MWb. The FTE with the highest flux content constitutes $\sim$ 1% of the net dayside open flux. These flux values are further compared against the estimates provided by the linear force-free flux-rope model. For the selected FTEs, the linear force-free model underestimated the flux content by up to 40% owing to the continuous reconnected flux injection.

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