Large‐amplitude GPS TEC variations associated with Pc5–6 magnetic field variations observed on the ground and at geosynchronous orbit
Large‐amplitude GPS TEC variations associated with Pc5–6 magnetic field variations observed on the ground and at geosynchronous orbit
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DOI：
10.1002/2015ja021517
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发表时间：
2015-09
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影响因子：
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通讯作者：
C. Watson;P. Jayachandran;H. Singer;R. Redmon;D. Danskin
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文献类型：
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作者：
C. Watson;P. Jayachandran;H. Singer;R. Redmon;D. Danskin
使用加拿大高北极电离层网络的高数据速率全球定位系统 (GPS) 接收器，观察到 Pc5-6 (<6.67 mHz) 频率下 GPS 总电子含量 (TEC) 的大幅变化。 2011 年 9 月 9 日，在中度地磁暴内极光活动频繁的时期，在午后区域的 2.5 小时内观察到 TEC 变化，峰峰值幅度为 2-7 TEC 单位（1 TECU = 1016 el m−2）。 TEC 观测来自努纳武特地区 Sanikiluaq（北纬 56.54°，东经 280.77°）位于极光区的 GPS 接收器。在同一时期，地球同步 GOES 13 磁力计和地面 Sanikiluaq 磁力计观测到了压缩的 Pc5-6 磁场变化。 GOES 13 的北磁足迹靠近 Sanikiluaq。互相关分析表明磁场和 TEC 变化可能存在关联。这一天没有报告任何能够激发 TEC 扰动的自然灾害或核爆炸。使用涉及多个 GPS 卫星的 TEC 测量的三角测量技术，还计算了电离层中 TEC 变化的传播速度。该计算揭示了两个不同的事件：向西传播的低频 (~0.9 mHz) TEC 变化，与 GOES 13 和 15 卫星观测到的压缩 Pc5 波向西传播一致，以及向南传播的高频 (~3.3 mHz) TEC 变化。这是第一份关于与 Pc5-6 ULF 波卫星观测相关的电离层 TEC 变化的报告。
Large‐amplitude variations in GPS total electron content (TEC) at Pc5–6 (<6.67 mHz) frequencies have been observed, using a high data rate Global Positioning System (GPS) receiver of the Canadian High Arctic Ionospheric Network. TEC variations with peak‐to‐peak amplitudes of 2–7 TEC units (1 TECU = 1016 el m−2) were observed over a 2.5 h period in the postnoon sector on 9 September 2011, during a period of high auroral activity within a moderate geomagnetic storm. TEC observations were from the Sanikiluaq, Nunavut (56.54°N, 280.77°E) GPS receiver located in the auroral region. Over this same time period, compressional Pc5–6 magnetic field variations were observed by the geosynchronous GOES 13 magnetometer and the ground‐based Sanikiluaq magnetometer. GOES 13 has a northern magnetic footprint in close proximity to Sanikiluaq. Cross‐correlation analysis indicates that magnetic field and TEC variations were possibly linked. No natural hazards or nuclear explosions capable of exciting TEC perturbations were reported on this day. Using a triangulation technique involving TEC measurements of multiple GPS satellites, the propagation velocity of TEC variations in the ionosphere was also calculated. This calculation revealed two distinct events: lower frequency (~0.9 mHz) TEC variations that propagated westward, consistent with the westward propagation of compressional Pc5 waves observed by GOES 13 and 15 satellites, and higher‐frequency (~3.3 mHz) TEC variations that propagated southward. This is the first report of variations in ionospheric TEC linked to satellite observations of Pc5–6 ULF waves.