Global dynamo simulation of ionospheric currents and their connection with the equatorial electrojet and counter electrojet: A case study
Global dynamo simulation of ionospheric currents and their connection with the equatorial electrojet and counter electrojet: A case study
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电离层电流的全球发电机模拟及其与赤道电射流和反电射流的联系：案例研究
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发表时间：
1983
期刊：
影响因子：
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通讯作者：
M. Crochet
中科院分区：
文献类型：
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作者：
C. Hanuise;C. Mazaudier;P. Vila;M. Blanc;M. Crochet
本文利用全球电离层风发电机模拟研究了平静日赤道和行星尺度电离层水平电流的相互关系。该模拟的目的是再现磁和雷达数据，首先是一个正常的安静的一天，然后为1977年1月21日，这是以前详细研究的相干后向散射雷达数据的基础上，为亚的斯亚贝巴位置的强反电喷流事件。对于参考平静日（1977年1月27日），低纬和中纬电流和电场的模式可以通过（1，−2）和（2，2）太阳潮的组合来大致再现。Sq电流系统和里士满等人[1980]从非相干散射数据导出的全局静电势分布都得到了很好的模拟。直接比较计算的电场与每个雷达站点的安静日平均值也显示出很好的协议上的东西分量，但一个较差的南北分量。通过拟合磁赤道处的H分量迹线和中纬度处的D迹线，进行了反电急流模拟。这个结果似乎给出了一个一致的解决方案之间的电连接赤道反electrojet和行星发电机层的问题。在中午扇形两侧的低纬地区，发现两个方向相反的水平流涡，上午为逆时针，下午为顺时针。它们都在中午在低纬度地区产生一个向极的电流，这是在磁记录上检测到的特征。逆电急流事件是由（2，2）和（2，4）太阳潮汐的组合再现的，假设周日潮汐对高度积分电流的贡献被抵消。这一结果与先前对反电射流现象的模拟研究相一致。
The interrelationship of equatorial and planetary scale ionospheric horizontal currents on quiet days is studied by means of a global ionospheric wind dynamo simulation. This simulation aims at reproducing magnetic and radar data first for a normal quiet day, and then for the strong counterelectrojet event of January 21, 1977, which was previously studied in detail on the basis of coherent backscatter radar data for the Addis-Ababa location. For the reference quiet day (January 27, 1977), the pattern of low and middle latitude currents and electric fields can be roughly reproduced by a combination of the (1,−2) and (2,2) solar tides. Both the Sq current system, and the global electrostatic potential distribution as derived by Richmond et al. [1980] from incoherent scatter data are well simulated. Direct comparison of the computed electric field with the quiet-day averages available for each radar site also show an excellent agreement on the east-west component, but a poorer one on the north-south component. The counterelectrojet simulation is performed by fitting the H component trace at the magnetic equator and the D trace at midlatitudes. The result appears to give a consistent solution to the problem of the electrical connection between the equatorial counterelectrojet and the planetary dynamo layer. Two horizontal current vortices of opposite directions are found to flow at low latitudes on each side of the noon sector, anticlockwise in the morning and clockwise in the afternoon. They both produce a poleward current flow at low latitudes at noon, a feature that is detected on the magnetic records. The counterelectrojet event is reproduced by a combination of the (2,2) and (2,4) solar tides, assuming that the contribution of the diurnal tide to the altitude-integrated current flow cancels out. This result is in agreement with a previous simulation study of the counterelectrojet phenomenon.