Statistical Study of EMIC Wave Propagation Using Space‐Ground Conjugate Observations
Statistical Study of EMIC Wave Propagation Using Space‐Ground Conjugate Observations
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DOI：
10.1029/2022ja030262
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发表时间：
2022-07
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通讯作者：
Sungjun Noh;Hyomin Kim;M. Lessard;M. Engebretson;V. Pilipenko;Eun‐Hwa Kim;J. Johnson;I. Kuzichev;Michelle Salzano
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文献类型：
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作者：
Sungjun Noh;Hyomin Kim;M. Lessard;M. Engebretson;V. Pilipenko;Eun‐Hwa Kim;J. Johnson;I. Kuzichev;Michelle Salzano
本文研究了电磁离子回旋波（EMIC）从源区到地面传播的观测特性。我们使用地球同步运行环境卫星（GOES）13（西经75 °的地球同步轨道卫星）和Sanikiluaq地面站（SNK，地理坐标为西经79.14 °和北纬56.32 °，偶极磁场为L = 6.0）上的磁强计，该地面站位于加拿大北方。利用这些磁共轭观测站，同时进行EMIC波观测。我们在GOES 13和SNK站之间共发现了295个重合和248个非重合EMIC波事件。我们的统计分析表明，重合事件主要是在白天观察到的。非重合事件的波法线角略高于重合事件。然而，波的重合主要取决于波的强度和持续时间。这是证实了地磁环境，其中显示较高的极光电射流（AE）和Kp指数的一致事件。我们还发现，一些事件显示出高频（f> 0.4 Hz）滤波。高频滤波和非滤波波事件的统计数据表明，两组之间以及电离层电子密度测量中存在明显的磁当地时间（MLT）和F10.7指数差异。此外，我们还发现了波动性质的差异，这可能表明磁层中的传播也起着重要的作用，在波过滤。
In the present study, we explore the observational characteristics of Electromagnetic Ion Cyclotron (EMIC) wave propagation from the source region to the ground. We use magnetometers aboard Geostationary Operational Environment Satellite (GOES) 13, the geosynchronous orbit satellite at 75°W, and at Sanikiluaq ground station (SNK, 79.14°W and 56.32°N in geographic coordinates, and L ∼ 6.0 in a dipole magnetic field) which is located in northern Canada. Using these magnetically conjugate observatories, simultaneous EMIC wave observations are carried out. We found a total of 295 coincident and 248 non‐coincident EMIC wave events between GOES 13 and the SNK station. Our statistical analysis reveals that the coincident events are predominantly observed on the dayside. The wave normal angles are slightly higher for the non‐coincident events than for coincident events. However, the coincidence of the waves is mostly governed by the intensity and duration of the wave. This is confirmed by the geomagnetic environment which shows higher auroral electrojet (AE) and Kp indices for the coincident events. We also found that some events show high‐frequency (f > 0.4 Hz) wave filtering. The statistics of the high‐frequency filtered and non‐filtered wave events show that there are clear magnetic local time (MLT) and F10.7 index differences between the two groups, as well as in ionospheric electron density measurements. In addition, we also found differences in the wave properties which possibly indicate that the propagation in the magnetosphere also plays an important role in the wave filtering.