Moderate geomagnetic storm (21-22 January 2005) triggered by an outstanding coronal mass ejection viewed via energetic neutral atoms
Moderate geomagnetic storm (21-22 January 2005) triggered by an outstanding coronal mass ejection viewed via energetic neutral atoms
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DOI：
10.1029/2009ja014663
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发表时间：
2010-08
影响因子：
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通讯作者：
S. McKenna-Lawlor;Lu Li;I. Dandouras;P. Brandt;Yihua Zheng;S. Barabash;R. Bučík;K. Kudela;J. Balaz;I. Strhárský
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文献类型：
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作者：
S. McKenna-Lawlor;Lu Li;I. Dandouras;P. Brandt;Yihua Zheng;S. Barabash;R. Bučík;K. Kudela;J. Balaz;I. Strhárský
[1]2005年1月20日的一次显著耀斑伴随着日冕物质抛射，于1月21日世界时1712分到达磁层顶，并产生了强烈的压缩压力脉冲。磁层活动增强。描述了2005年1月21-22日02.19 UT期间，双星星星和IMAGE（Imager for Magnetopause-to-Aurora Global Exploration）航天器上记录的高能中性原子（ENA）数据中的环电流扰动的相关发展。1月21日1712 UT的磁暴在1月22日0600 UT达到最小Dst = 101 nT，并持续到1月27日。ENA数据表明，环电流经历了一个深注入的H+和O+离子在1830 UT时，IMF Bz取向南。在这个时候，环电流是强烈的不对称，虽然后来变得更加对称。Bz于UT 1946转往北。从1月22日协调世界时0224分到0612分，Bz的波动使得它间歇性地指向南方（±10 nT）。中等，但扩展的地磁层的强压力脉冲的响应被解释为一个缓慢的演变，在增强的等离子体片密度的条件下的取向BZ。动态参数的建模，代表各种电流系统，有助于DST显示其各自的特点。还模拟了变化的地磁场。与ENA数据的比较表明，早期记录在氢和氧的不对称增强伴随着加强外部电流系统，产生磁场相关的压缩磁层。环电流不对称性的逐渐减少得到了相应的、仍然增强的模拟磁场所显示的大部分对称配置的补充。
[1] An outstanding flare on 20 January 2005 was accompanied by a coronal mass ejection which arrived at the magnetopause at ∼1712 UT, 21 January, and produced a strong compression-pressure pulse. Enhanced magnetospheric activity was stimulated. The associated development between 02.19 UT on 21–22 January, 2005 of a ring current disturbance in energetic neutral atom (ENA) data, recorded aboard both the Double Star and the IMAGE (Imager for Magnetopause-to-Aurora Global Exploration) spacecraft, is described. A magnetic storm from ∼1712 UT, 21 January, reached minimum Dst = ∼−101 nT at ∼0600 UT, 22 January, and its recovery phase endured until 27 January. ENA data indicate that the ring current experienced a deep injection of H+ and O+ ions at ∼1830 UT when IMF Bz was oriented southward. At this time, the ring current was strongly asymmetric, although later it became more symmetric. Bz turned northward at 1946 UT. From ∼0224 to ∼0612 UT on 22 January, Bz fluctuated such that it intermittently pointed southward (±10 nT). The moderate but extended response of the geomagnetosphere to the strong pressure pulse is explained by a slow evolution in the orientation of Bz under conditions of enhanced plasma sheet density. Modeling of dynamical parameters that represent various current systems that contributed to Dst revealed their individual characteristics. The changing geomagnetic field was also modeled. Comparisons with ENA data show that early asymmetric enhancements recorded in hydrogen and oxygen were accompanied by intensified external current systems that produced a magnetic field related compression of the magnetosphere. The gradual reduction in ring current asymmetry was complemented by the largely symmetrical configuration displayed by the corresponding, still intensified, modeled magnetic field.