[P-EM06] Magnetospheric Multi-Scale (MMS) mission -- A new age of magnetospheric physics

[PEM06-P05] Scaling-law for early-stage development of magnetic reconnection

*清水 健矢¹、藤本 正樹^2,1、篠原 育² (1.東京大学大学院理学系研究科、2.宇宙航空研究開発機構/宇宙科学研究所)

キーワード：Magnetic Reconnection

A scaling-law for early-stage development of magnetic reconnection has been found from comparing two-dimensional particle simulation results of anti-parallel magnetic reconnection (asymptotic field denoted by B₀) with different current sheet thicknesses (D) and different ion-to-electron mass ratios (M). In these runs, magnetic reconnection is initiated by adding non-zero magnetic field normal to the current sheet. When the reconnected flux (in the B₀ D unit) at various times is plotted versus re-scaled reconnection electric field E_rx D^1/2 (E_rx in the V_A B₀ unit, where V_A is the relevant Alfven speed) obtained simultaneously, by which procedure a curve is obtained from each run, the curves obtained from the early development phases (reconnected flux < 2) of various runs are found to overlap among themselves. The spatial structures of some quantities around the X-lines determine the reconnection rates. Sampling the spatial profiles obtained when the same amount of magnetic flux is reconnected from different runs, we confirm that the non-dependence on M and the D^1/2-scaling of the reconnection rate are consistent with how the spatial scales vary according to M and D.