An empirical model of ground-level geomagnetic perturbations
An empirical model of ground-level geomagnetic perturbations
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DOI：
10.1002/swe.20030
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发表时间：
2013-03-01
影响因子：
3.7
通讯作者：
Weimer, D. R.
中科院分区：
文献类型：
--
作者：
Weimer, D. R.
提出了一种新的预测地面地磁扰动的经验模型。该模型基于北半球多个站点在8年期间收集的全球磁场测量数据，以及同时测量的行星际磁场（IMF）。电离层电导率的变化隐含在模型构建中使用的测量中，包括太阳F-10.7指数。该模型提供了IMF、太阳风速度、偶极子倾角（季节）和F-10.7指数，计算了指定位置磁扰动的所有三个矢量分量。模型结果与相应的电离层电势图一致。有趣的是，垂直分量图的模式与头顶电离层磁场排列的电流图相似。将模型计算与不同地点的测量结果进行比较，结果非常好，特别是在低频时。更高频率的随机变化不能很好地用模型再现，但它们往往与预测水平成比例地发生。该模型可用于提供大约提前1小时的地磁活动区域预报。引用本文：Weimer， d.r.(2013)，地面地磁扰动的经验模型，空间天气，11,107-120,doi:10.1002/ swee .20030
A new empirical model for predicting ground-level geomagnetic perturbations has been developed. This model is based on global measurements of the magnetic field at multiple stations in the Northern Hemisphere collected over an 8 year period, along with the simultaneous measurements of the interplanetary magnetic field (IMF). Variations in ionospheric conductivity are implicitly contained in the measurements used in the model's construction, including the solar F-10.7 index. Provided with the IMF, solar wind velocity, dipole tilt angle (for season), and F-10.7 index, this model computes all three vector components of the magnetic perturbations at specified locations. The model results are consistent with the corresponding maps of the ionospheric electric potential. Interestingly, maps of the vertical component have patterns that resemble maps of the overhead, ionospheric field-aligned currents. Comparisons of model calculations with measurements at different locations show very good results, particularly at low frequencies. There are random variations at higher frequencies that are not reproduced well with the model, but they tend to occur in proportion to the predicted levels. This model could be useful for providing regional forecasts of geomagnetic activity with an approximately 1 h lead time. Citation: Weimer, D. R. (2013), An empirical model of ground-level geomagnetic perturbations, Space Weather, 11, 107-120, doi:10.1002/swe.20030