Statistical characteristics of field-aligned currents in Saturn's nightside magnetosphere
Statistical characteristics of field-aligned currents in Saturn's nightside magnetosphere
复制标题
土星夜侧磁层场对准电流的统计特征
DOI：
--
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
M. Dougherty
中科院分区：
文献类型：
--
作者：
D. Talboys;E. Bunce;S. Cowley;C. Arridge;A. Coates;M. Dougherty
[1]在2008年，卡西尼号宇宙飞船穿越土星的高纬度场向电流系统，在夜侧磁层连续的南北近心点通过。两种类型的电流系统先前已被确定，与反对称方位场签名在北方和南半球。第一个展品完全“滞后”场形态，而第二个还包括一个赤道向间隔的“领先”场。在这里，我们报告这些电流的统计特性，它们的强度，电离层的位置，和等离子体边界的关系。第一类由高纬到低纬为先下降后上升的气流，其强度为0.5- 3.5MA/弧度。下行电流在北半球和南半球分别映射到电离层共纬度为<$13.5 °和<$16 °，通常集中在外磁层，而上行电流在北半球和南半球分别映射到电离层共纬度为<$16.5 °和<$19 °，位于环电流区内。第二类是在开放磁场和外磁层区流动的一个101 -2 MArad的分布向下电流，随后在南北方向分别映射到1015.5 °和1018 °的一个102.5 -5 MArad的向上电流，对应于外磁层和外环电流。在南北方向分别有一个向下的流场，对应于内环流场，南北方向分别为17.5°和120 °，向下的流场为101 - 2.5MArad。
[1] During 2008, the Cassini spacecraft traversed Saturn’s high‐latitude field‐aligned current systems on sequential north–south periapsis passes in the nightside magnetosphere. Two types of current systems have previously been identified, associated with antisymmetric azimuthal field signatures in the northern and southern hemispheres. The first exhibits exclusively “lagging” field morphology, while the second also includes an equatorward interval of “leading” field. Here we report the statistical characteristics of these currents, their strength, ionospheric location, and relationship to plasma boundaries. From high to low latitude, the first type comprises a downward current followed by an upward current, whose strengths are ∼0.5–3.5 MA per radian of azimuth. The downward current maps to ionospheric colatitudes of ∼13.5° and ∼16° in the north and south, respectively, usually centered in the outer magnetosphere, while the upward current maps to ∼16.5° and ∼19° in the north and south, located within the ring current region. The second type comprises a distributed downward current of ∼1–2 MA rad flowing in the open field and outer magnetosphere regions, followed by an upward current of ∼2.5–5 MA rad mapping to ∼15.5° and ∼18° in the north and south, corresponding to the outer magnetosphere and outer ring current, and a further downward current of ∼1–2.5 MA rad mapping to ∼17.5° and ∼20° in the north and south, corresponding to the inner ring current.
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DOI：
10.1029/2008ja013257
发表时间：
2008-09
期刊：
Scopus
影响因子：
--
作者：
E. Bunce;C. Arridge;J. Clarke;A. Coates;S. Cowley;M. Dougherty;Jean-Claude Gérard;D. Grodent;K. Hansen;J. Nichols;D. Southwood;D. Southwood;D. Talboys
通讯作者：
E. Bunce;C. Arridge;J. Clarke;A. Coates;S. Cowley;M. Dougherty;Jean-Claude Gérard;D. Grodent;K. Hansen;J. Nichols;D. Southwood;D. Southwood;D. Talboys
土星高纬度磁层中异常的场对准电流特征：卡西尼号革命期间数据的分析 89
DOI：
10.1029/2010ja015612
发表时间：
2010
期刊：
Space Physics
影响因子：
--
作者：
Bunce E
通讯作者：
Bunce E
土星白天磁层的磁场结构及其到电离层的映射：环流模型的结果
DOI：
10.1029/2007ja012538
发表时间：
2008
期刊：
Space Physics
影响因子：
--
作者：
Bunce E
通讯作者：
Bunce E
土星赤道磁层中行星周期附近的磁场振荡：振幅和相位随径向距离和当地时间的变化
DOI：
10.1029/2009ja014729
发表时间：
2010
期刊：
Space Physics
影响因子：
--
作者：
Andrews D
通讯作者：
Andrews D