Evidence of near‐Earth breakup location
Evidence of near‐Earth breakup location
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近地分裂位置的证据
DOI：
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
A. Yahnin
中科院分区：
文献类型：
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作者：
S. Dubyagin;V. Sergeev;C. Carlson;S. Marple;T. Pulkkinen;A. Yahnin
我们报告了一个详细的研究，一个孤立的亚暴开始与FAST航天器穿越赤道=最极光弧时/它开始破裂的地方。综合地面（光学、测热计和磁强计）数据，结合空间场和粒子高分辨率观测，可以推断出在这一有充分记录的事件中破裂起始区域的以下特性：(1)电弧磁通管停留在相当大的等离子体压力梯度区域，压力值接近1 - 2 nPa。弧位于(2)质子各向同性（b2i）边界的极向0.4°（大致给出赤道磁场的约40 nT估计）和(3)接近扩散电子沉淀的峰值。(4) Tsyganenko 96模型对这些特殊的太阳风条件（与观测到的b2i边界和估计的等离子体压力都很吻合）将弧映射到赤道距离~ 8RE。所有这些事实都一致地证明，在这种特殊情况下，极光破裂是在r ~ 8RE磁尾的近地域发射的。
We report a detailed study of an isolated substorm onset with the FAST spacecraft crossing the equatorward = most auroral arc just when/where it starts to break up. Comprehensive ground (optical, riometer and magnetometer) data combined with the space borne field and particle high resolution observations allowed to infer the following properties of the breakup onset region in this well‐documented event: (1) The arc flux tube stays in the region of considerable plasma pressure gradient wherethe pressure values are close to ∼1–2 nPa. The arc was located (2) just 0.4° poleward of the proton isotropic (b2i) boundary (which roughly gives ∼40 nT estimate for the equatorial magnetic field) and (3) close to the peak of the diffuse electron precipitation. (4) Tsyganenko 96 model for these particular solar wind conditions (which correspond well to both the observed b2i boundary and estimated plasma pressure) maps the arc to the equatorial distance of ∼8RE.All these facts in mutual agreement evidence that the auroral breakup in this particular case was launched in the near‐Earth domain of the magnetotail at r ∼8RE.