Joint Study on the M-I Coupling in the Southern Polar Cap

南极冠 M-I 耦合联合研究

• 批准号: 09044053
• 负责人: FUKUNISHI Hirishi
• 金额: $ 5.06万
• 依托单位: TOHOKU UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B).
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09044053/
• 关键词: Antarctica; geomagnetic field; ULF wave; aurora; polar cap; Pc 3; Pc 5; Pc 1

Data obtained by Automatic Geophysical Observatories (AGOs) located at Antarctic high latitude areas in the period of 1993 - 1997, such as aurora image, geomagnetic field, CAN, and VLF waves, have been analyzed carefully in order to investigate the mechanisms of aurora and geomagnetic activities in polar cap region, comparing with Super DARN HF radar network and satellite data. The most important findings are as follows : 1) Pc 1 bursts occur in polar cap region as well as cusp and cleft region, accompanying an impulsive geomagnetic variation caused by geomagnetic reconnection. 2) Pc 3 waves are frequently observed during daytime near 70 degree in geomagnetic latitude, while around 80 degree local time dependency of Pc 3 is comparably small. Based on the comparison with interplanetary magnetic field (IMF) it is inferred that Pc 3 source is located at upstream of shock front and the Pc 3 penetrates into the magnetosphere from subsolar region for small cone angle case while from high latitude in the tail region or low latitude boundary layer (LLBL) for large cone angle case. 3) Dynamic spectrum of Pc 5 in geomagnetic latitude range of 72 - 74 degree sometimes shows an arch structure caused by odd resonance wave. The occurrence frequency of Pc 5 becomes large in northward IMF condition, which implies relationship between generation of Pc 5 and geomagnetic reconnections. 4) Magnetic impulse event (MIE) occurs in the convection reversal boundary of 4 cell pattern observed in the case of northward IMF. MIE travels westward by 60 degree in longitude at a speed of 2 km/sec.

利用1993 ~ 1997年南极高纬度地区自动地球物理观测站（AGO）的极光图像、地磁场、CAN和VLF波等资料，通过与超短波雷达网和卫星资料的对比，对极冠区极光和地磁活动的机制进行了研究。最重要的发现如下：1）Pc 1爆发发生在极帽区以及尖点和裂区，伴随着地磁重联引起的脉冲式地磁变化。2)在地磁纬度70度附近的白天观测到的Pc 3波最多，而在80度附近的Pc 3波对当地时间的依赖性很小。通过与行星际磁场（IMF）的比较，推测Pc 3源位于激波前缘的上游，小锥角情况下Pc 3从太阳下区域进入磁层，大锥角情况下Pc 3从尾区高纬或低纬边界层（LLBL）进入磁层。3)在地磁纬度72 - 74度范围内，Pc 5的动力学谱有时会出现由奇共振波引起的拱形结构。在IMF向北的情况下，Pc 5的出现频率变大，这暗示Pc 5的产生与地磁重联有关系。4)在北向IMF的情况下，磁脉冲事件（MIE）发生在4单体型对流反转边界。MIE以2公里/秒的速度向向西60度移动。

项目成果

M.Sato,H.Fukunishi,L.J.Lanzerotti,C.G.Maclennan: "Magnetic impulse events and related Pc1 bursts observed by the AGO network in Antarctica" Journal of Geophysical Research(in press). 104. (1999)

M.Sato、H.Fukunishi、L.J.Lanzerotti、C.G.Maclennan：“南极洲 AGO 网络观测到的磁脉冲事件和相关 Pc1 爆发”地球物理研究杂志（正在出版）。

Sato M.,H.Fukunishi,L.J.Lanzerotti and C.G.Maclennan: "Magnetic impulse events and related Pcl bursts observed by the Automatic Geophysical Observatories network in Antarctica"J.Geophys.Res.. 104. 19,971-19,982 (1999)

Sato M.、H.Fukunishi、L.J.Lanzerotti 和 C.G.Maclennan：“南极洲自动地球物理观测站网络观测到的磁脉冲事件和相关 Pcl 爆发”J.Geophys.Res.. 104. 19,971-19,982 (1999)

Lanzerotti, L.J., A. Shono, H. Fukunishi and C.G. Maclennan: "Long-period hydromagnetic waves at very high geomagnetic latitudes"J. Geophys. Rs.. 104(9). 28423-28435 (1999)

Lanzerotti, L.J.、A. Shono、H. Fuukunishi 和 C.G.

L.Jlanzerotti,A.Shono,H.Fukunishi,C.G.Maclennan: "Long-Period hydromagnetic waves very high geomagnetic latitudes"Journal of Geophysical Research. 104. 28,423-28,435 (1999)

L.Jlanzerotti、A.Shono、H.Fukunishi、C.G.Maclennan：“长周期水磁波非常高的地磁纬度”地球物理研究杂志。

L.D.Dyrud, H.Fukunishi 他: "Ground observations and possible source regions of two types of Pc 1-2 micropulsations at very high latitudes" Journal of Geophysical Research. 102・A12. 27011-27027 (1997)

L.D.Dyrud、H.Fukunishi 等：“极高纬度地区两种类型的 Pc 1-2 微脉动的地面观测和可能的源区”《地球物理研究杂志》102・A12（1997 年）。