Derivation of inner magnetospheric electric field (UNH-IMEF) model using Cluster data set
Derivation of inner magnetospheric electric field (UNH-IMEF) model using Cluster data set
复制标题
使用 Cluster 数据集推导内磁层电场 (UNH-IMEF) 模型
DOI：
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
R. Torbert
中科院分区：
文献类型：
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作者：
H. Matsui;P. Puhl;V. Jordanova;Y. Khotyaintsev;P. Lindqvist;R. Torbert
利用2001年2月至2006年10月5年多的星团磁场资料，建立了L =2-10的内磁层电场（UNH-IMEF）模型。该电场数据集被划分为几个由ACE测量的行星际电场（IEF）瓦尔- ues范围。由于环电流模拟需要以电场作为输入参数，通常在L=2-6.6范围内进行，我们在我们的数据集（L4）中包括了地面雷达和低高度卫星在Clus ter近地点内的统计结果。通过求解反问题，从平均电场导出电势模式。小IEF值的电势模式可能受到电离层发电机的影响。在傍晚附近，随着IEF的增加，电场强度也随之增加，这可能是由于亚极光偏振流（SAPS）的作用。另一个在大IEF期间电场增强的区域位于L>8的9 MLT附近，这可能与太阳风-磁层耦合有关。我们的潜在模式是一致的，帐篷与那些来自自洽模拟。由于电位模式可以内插/外推到测量范围内的任何离散IEF值，因此我们推导出经验电位模型。通过比较由该模型导出的电场与由Cluster测量并映射到赤道的原始电场来评估该模型的性能。该模型通过我们的网站向公众开放。
We derive an inner magnetospheric electric field (UNH-IMEF) model atL=2-10 using primarily Cluster elec- tric field data for more than 5 years between February 2001 and October 2006. This electric field data set is divided into several ranges of the interplanetary electric field (IEF) val- ues measured by ACE. As ring current simulations which re- quire electric field as an input parameter are often performed at L=2-6.6, we have included statistical results from ground radars and low altitude satellites inside the perigee of Clus- ter in our data set (L 4). Electric potential patterns are de- rived from the average electric fields by solving an inverse problem. The electric potential pattern for small IEF values is probably affected by the ionospheric dynamo. The mag- nitudes of the electric field increase around the evening lo- cal time as IEF increases, presumably due to the sub-auroral polarization stream (SAPS). Another region with enhanced electric fields during large IEF periods is located around 9 MLT at L>8, which is possibly related to solar wind- magnetosphere coupling. Our potential patterns are consis- tent with those derived from self-consistent simulations. As the potential patterns can be interpolated/extrapolated to any discrete IEF value within measured ranges, we thus derive an empirical electric potential model. The performance of the model is evaluated by comparing the electric field de- rived from the model with original one measured by Cluster and mapped to the equator. The model is open to the public through our website.