Evolution of the magnetic field structure outside the magnetopause under radial IMF conditions
學年 105
學期 2
出版（發表）日期 2017-04-04
作品名稱 Evolution of the magnetic field structure outside the magnetopause under radial IMF conditions
作品名稱（其他語言）
著者 Gilbert Pi; Jih-Hong Shue; Kostiantyn Grygorov; Hsien-Ming Li; Zdeněk Němeček; Jana Šafránková; Ya-Hui Yang; Kaiti Wang
單位
出版者
著錄名稱、卷期、頁數 Journal of Geophysical Research: Space Physics 122(4), p.4051–4063
摘要 We use the Time History of Events and Macroscale Interactions during Substorms data to investigate the magnetic field structure just outside the magnetopause and its time evolution for radial interplanetary magnetic field (IMF) events. When the magnetic field drapes around the magnetopause in the magnetosheath region, an asymmetric magnetic field orientation in different hemispheres is expected. Our two-case study reveals some conflicts with the predicted draped field configuration in the Southern Hemisphere. The magnetosheath Bz component had a different sign depending on the upstream IMF Bx component's polarity at the beginning of the radial IMF intervals. With time, the observed Bz became northward in both cases with increasing positive values through the events. The increasing value of the Bz component may be explained by two possible mechanisms: by a change of the upstream IMF and by a reconnection between magnetosheath and magnetospheric field lines. Our study shows that both mechanisms contributed to the observed changes. Thus, there was a correlation between the change of the upstream IMF conditions and an increase in the magnetosheath northward magnetic field component. The observed formation of the boundary layer near the magnetopause proves that the reconnection process was ongoing at least for a part of the time. We suggest two possible reconnection scenarios: one near subsolar point and another tailward of the one cusp due to lobe reconnection. The asymmetry of reconnection locations causes rearrangement of the magnetic field structure near the magnetopause and turns the observed magnetosheath Bz component even further into positive values.
關鍵字 magnetic field;radial IMF;magnetosheath
語言 en_US
ISSN 2156-2202
期刊性質 國外
收錄於 SCI
產學合作
通訊作者 Jih-Hong Shue
審稿制度 是
國別 USA
公開徵稿
出版型式 ,電子版
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機構典藏連結 ( http://tkuir.lib.tku.edu.tw:8080/dspace/handle/987654321/110168 )

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