...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Earth, planets and space: EPS >Equatorial electrojet as a diagnostic tool of geomagnetic field models
【24h】

Equatorial electrojet as a diagnostic tool of geomagnetic field models

机译：赤道电喷作为地磁场模型的诊断工具

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The equatorial electrojet (EEJ) is a unique feature of the Earth's external current systems because it must flow along the dip equator. This provides us with a tool to determine the nature of the variations imposed by competing main field models on the equatorial region. First we show that for certain regions a comparison between scalar geomagnetic measurements that use different models to remove the main field may not be reasonable. Next we found the intrinsic error in the determination of the possible location of the dip equator was +/- 9.8 km (0.088 degrees) at 108 km altitude for the models shown here. Using scalar measurements from over 14,000 CHAMP satellite passes, the latitude of the maximum of the EEJ field at the satellite altitude was determined by subtracting four different models of the main field. We find that the location can be statistically determined to within +/- 0.5 degrees of the dip equator (calculated at 108 km altitude) irrespective of longitude, time of the measurement, degree of magnetic activity, and subtracted model. However, variations of the latitude of the maximum EEJ field with longitude are sometimes caused by the actual model and are not always a physical phenomenon. By choosing one model, and assuming it is the best representation of the main field, we have also shown that the accuracy of determination of the position of the EEJ signal is reduced in the morning and evening hours and that a morning and evening shift in the location of the EEJ found using ground measurements is also seen here. There exists a clear annual variation in the position of the EEJ regardless of longitude: it is south of the dip equator in December which is in agreement with the findings of all previous studies.
机译：赤道电喷（EEJ）是地球外部电流系统的独特功能，因为它必须沿着倾角赤道流动。这为我们提供了一种工具，可以确定由赤道区域上竞争性主场模型引起的变化的性质。首先，我们表明，对于某些区域，使用不同模型消除主磁场的标量地磁测量之间的比较可能是不合理的。接下来，对于此处显示的模型，在确定倾角赤道的可能位置时，发现固有误差为+/- 9.8 km（0.088度），位于108 km高度。使用从14,000多个CHAMP卫星通道进行的标量测量，通过减去主场的四个不同模型来确定EEJ场在卫星高度的最大纬度。我们发现，无论经度，测量时间，磁活动度和减法模型如何，都可以从统计角度确定倾角赤道的+/- 0.5度以内（在108 km高度处计算）。但是，最大EEJ场的纬度随经度的变化有时是由实际模型引起的，并不总是物理现象。通过选择一个模型，并假设它是主要领域的最佳代表，我们还表明，在早晚时段，确定EEJ信号位置的准确性降低了，而在此处还可以看到使用地面测量发现的EEJ的位置。不论经度如何，EEJ的位置每年都存在明显的年度变化：它位于12月位于赤道以南，这与以前的所有研究结果一致。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号