Impact of the solar wind dynamic pressure on the Region 2 field-aligned currents
Impact of the solar wind dynamic pressure on the Region 2 field-aligned currents
复制标题
太阳风动压对区域 2 场对准电流的影响
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
T. Higuchi
中科院分区：
文献类型：
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作者：
S. Nakano;G. Ueno;S. Ohtani;T. Higuchi
利用f13国防气象卫星（DMSP-F13）的磁场资料，研究了2区场向流与太阳风动压的关系。区域2电流的产生与磁层中磁压力梯度的方向有关，与热压力梯度的方向有关。过去的航天器观测表明，磁层中磁压的空间分布随太阳风动压的变化而变化。因此，我们可以预期，区域2的电流将取决于太阳风动压。我们比较了利用DMSP-F13的磁场数据得到的电离层高度的2区场向电流强度与OMNI2每小时数据得到的太阳风动压。证实了磁暴期间2区电流强度与太阳风动压有关。然而，在非风暴时期，2区电流与太阳风动压之间的相关性较弱。非风暴时期的弱相关性表明，环流区等离子体压力对太阳风动压对2区电流的影响也是必不可少的。
[1] The relationship between the Region 2 field-aligned currents and the solar wind dynamic pressure is investigated using magnetic field data from Defense Meteorological Satellite Program-F13 (DMSP-F13). The generation of the Region 2 currents is associated with the direction of the magnetic pressure gradient in the magnetosphere, in relation to that of the thermal pressure gradient. Past spacecraft observations have suggested that the spatial distribution of the magnetic pressure in the magnetosphere varies with the solar wind dynamic pressure. Therefore, we can expect that the Region 2 currents would depend on the solar wind dynamic pressure. We compared the Region 2 field-aligned current intensity at the altitude of the ionosphere, as derived using magnetic field data from DMSP-F13, with the solar wind dynamic pressure derived from OMNI2 hourly data. It was confirmed that the Region 2 current intensity depends on the solar wind dynamic pressure during magnetic storms. During nonstorm times, however, the correlation between the Region 2 currents and the solar wind dynamic pressure is weak. The weak correlation during nonstorm times suggests that the plasma pressure in the ring current region is also essential for the effect of the solar wind dynamic pressure on the Region 2 currents.