极盖区等离子体云块触发的极向边界点亮事件的观测研究

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国家科技期刊平台
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中文摘要：极盖区等离子体云块是电子密度比背景高出 2 倍及以上的高密度不均匀体，极向边界点亮是夜侧极光卵极向边界亮度显著增强的极光结构。探究极盖区等离子体云块与极向边界点亮现象的形成和演化以及二者之间的关系对理解极区电离层-磁层耦合具有重要意义。本文基于北极黄河站全天空极光成像仪、欧洲非相干散射雷达(EISCAT)、SuperDARN 雷达和 GPS TEC 等多手段观测数据，揭示极盖区等离子体云块运动到夜侧极光卵极向边界，进而触发极向边界点亮的完整过程。研究结果表明，(1)高密度等离子体云块从极盖区运动到夜侧极光卵极向边界时，极向边界附近的极光强度明显增加，即出现了极向边界点亮现象。(2)极光亚暴发生后，极光卵极向膨胀，极向边界到达EISCAT Svalbard 42 m雷达观测视野。该雷达观测到了高密度、高电子和离子温度的结构，并伴随着电子密度峰值高度下降和离子上行等现象，这与高密度等离子体云块的输运和当地的极光粒子沉降密切相关。(3)从日侧向夜侧输运的等离子体云块到达夜侧极光卵极向边界附近时可能触发极向边界点亮，并且影响等离子体云块和极光粒子沉降接触区域的等离子体特征，这有助于加深我们对夜侧极区电离层-磁层耦合过程的理解。

外文标题：Observation of poleward boundary intensification events triggered by polar cap patches

外文摘要：Polar cap patches are common high-density irregularities in the polar cap ionosphere with electron den-sities of more than twice the background density.Poleward boundary intensifications(PBI)are auroral structures characterized by significantly enhanced brightness of the nightside auroral oval at its poleward boundary.Understanding PBI formation,evolution,and relationship with polar cap plasma is crucial to study the process of polar ionosphere-magnetosphere coupling.In this work,we analyzed the complete PBI gen-eration process triggered by polar cap patches moving to the poleward boundary of the nightside auroral oval,using observational data from the all-sky auroral imager of the Arctic Yellow River Station,the European Incoherent Scatter(EISCAT)radars,and total electron content data from the GPS receivers.The results in-dicate that high-density plasma moved antisunward and reached the nightside poleward boundary of the auroral oval,markedly enhancing the local auroral intensity and triggering PBI events.When substorms in-duced a poleward expansion of the nightside auroral oval,EISCAT Svalbard 42 m radars observed high-density plasma structures with high electron and ion temperatures,as well as a decrease of the electron den-sity peak height and an ion upflow,both explained by high-density plasma vertical transport and particle precipitation.This implies that plasma transported from the polar cap region to the nightside auroral oval effectively triggered PBI events that in turn,influenced the plasma characteristics.This analysis clarifies ionosphere-magnetosphere coupling processes in the nightside polar region.

外文关键词：

polar cap patchespoleward boundary intensificationauroral substormsionospheric convec-tionArctic

作者：

赵变龙、邢赞扬、张清和、马羽璋、王勇、胡泽骏、张佼佼、王翔宇、陆盛、张端

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作者单位：

山东大学空间科学研究院,山东威海 264209

中国极地研究中心(中国极地研究所),上海 200136

中国科学院国家空间科学中心,北京 101408

关键词：

极盖区等离子体云块极向边界点亮极光亚暴电离层对流北极

基金：

国家自然科学基金国家自然科学基金山东省自然科学基金山东省自然科学基金小米青年学者项目电波环境特性及模化技术国家重点实验室项目中国电波传播研究所稳定支持科研经费资助项目国家博士后科学基金

项目编号：

4212010400342204164ZR2022MD034ZR2022QD0776142403180204A1323121912021M701974

出版年：

2024

DOI：

10.13679/j.jdyj.20240009

极地研究

国家海洋局极地考察办公室中国极地研究中心

极地研究

CSTPCD北大核心

影响因子：0.638

ISSN：1007-7073

年,卷(期)：2024.36(1)

参考文献量40