Associating ground magnetometer observations with current or voltage generators
Associating ground magnetometer observations with current or voltage generators
复制标题
将地面磁力计观测与电流或电压发生器相关联
DOI：
10.1002/2017ja024140
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
A. Willer
中科院分区：
文献类型：
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作者：
M. Hartinger;Z. Xu;C. Clauer;Y. Yu;D. Weimer;H. Kim;V. Pilipenko;D. Welling;R. Behlke;A. Willer
磁层-电离层电流系统的电路类比对于电离层电流的驱动器有两个极端：电离层电场/电压恒定而电流/电导率变化-“电压发生器”-和电流恒定而电场/电导率变化-“电流发生器”。地面磁强计观测的统计研究与昼侧瞬态高纬度电流系统（THLCS）驱动类似的机制发现矛盾的结果，使用这种范式：一些研究THLCS与电压发生器，其他与电流发生器。我们认为，这种矛盾的大部分来自用于解释地面磁力计观测的两个假设：（1）在相对于THLCS场向电流的固定位置进行的测量和（2）极光降水对电离层电导率的贡献可以忽略不计。我们使用的观察和模拟来说明这两个假设如何大大改变与电流或电压发生器相关的磁扰动的预期。我们的研究结果表明，在解释电流/电压发生器背景下THLCS的地面磁力计观测之前，需要考虑地面磁力计站相对于THLCS场向电流的位置以及任何极光区电导率增强的位置。
A circuit analogy for magnetosphere‐ionosphere current systems has two extremes for drivers of ionospheric currents: ionospheric electric fields/voltages constant while current/conductivity vary—the “voltage generator”—and current constant while electric field/conductivity vary—the “current generator.” Statistical studies of ground magnetometer observations associated with dayside Transient High Latitude Current Systems (THLCS) driven by similar mechanisms find contradictory results using this paradigm: some studies associate THLCS with voltage generators, others with current generators. We argue that most of this contradiction arises from two assumptions used to interpret ground magnetometer observations: (1) measurements made at fixed position relative to the THLCS field‐aligned current and (2) negligible auroral precipitation contributions to ionospheric conductivity. We use observations and simulations to illustrate how these two assumptions substantially alter expectations for magnetic perturbations associated with either a current or a voltage generator. Our results demonstrate that before interpreting ground magnetometer observations of THLCS in the context of current/voltage generators, the location of a ground magnetometer station relative to the THLCS field‐aligned current and the location of any auroral zone conductivity enhancements need to be taken into account.