极地研究 ›› 2012, Vol. 24 ›› Issue (3): 274-283.DOI: 10.3724/SP.J.1084.2012.00274

• 研究论文 • 上一篇    下一篇

日侧弥散极光对太阳风动压增强的响应

陈相材1,2,韩德胜1,胡泽骏1,刘建军1,3,胡红桥1,邢赞扬1,4,刘俊明1,刘瑞源1   

  1.  
    1中国极地研究中心国家海洋局极地科学重点实验室,上海 200136;
    2内蒙古师范大学物理与电子信息学院,内蒙古 呼和浩特 010022;
    3武汉大学电子信息学院,湖北 武汉 430070; 4西安电子科技大学理学院,陕西 西安 710071
  • 收稿日期:2012-01-16 修回日期:2012-03-22 出版日期:2012-09-30 发布日期:2012-09-30
  • 通讯作者: 韩德胜
  • 基金资助:

    小尺度极光结构的多尺度并行观测与研究;日侧重联极光的多波段观测和产生机制研究;日侧冕状极光的分类及其产生机制研究;日侧极光粒子沉降的能谱特征研究;极区能量沉积过程及其对120E子午面电离层影响的研究;极区海洋大气与空间环境业务化监测及其在气候变化预测中的应用;日侧极光粒子沉降的能谱特征研究;南北极环境综合考察与评估专项

DAYSIDE DIFFUSE AURORA RESPONSE TO AN INCREASE OF SOLAR WIND DYNAMIC PRESSURE

  Chen Xiangcai1, 2, Han Desheng1, Hu Zejun1, Liu Janjun1, 3, Hu Hongqiao1, Xing Zanyang1, 4, Liu Junming1, Liu Ruiyuan1   

  • Received:2012-01-16 Revised:2012-03-22 Online:2012-09-30 Published:2012-09-30

摘要: 太阳风动压的显著变化能导致沉降进入极区电离层的能量粒子通量以及磁层-电离层电流系发生扰动。磁层高能粒子沉降到极区上层大气并与中性气体碰撞所激发的弥散极光,能够对这种扰动做出相应的响应。基于斯瓦尔巴特(Svalbard)群岛新奥尔松(Ny-?lesund)地区北极黄河站优越的地理优势,我们利用安装在黄河站的极光全天空成像仪观测到了日侧弥散极光对太阳风动压增强的响应。通过2006年1月2日事件观测显示,随着太阳风动压的增强,日侧弥散极光在极光卵赤道向部分首先点亮并逐渐向高纬扩展,同时地磁环境也受到相应扰动影响。我们认为,随着太阳风动压的增强,日侧磁层顶受到压缩,磁层内波粒相互作用导致投掷角散射增强,使得沉降进入极光卵赤道侧电离层的高能粒子数密度增大,进而导致日侧弥散极光强度增强。

关键词: 日侧弥散极光, 行星际磁场, 太阳风动压, 地磁活动

Abstract: The sudden enhancement of solar wind dynamic pressure can result in the disturbance on the flux of energetic particles precipitating into the ionosphere and the current intensity in magnetosphere-ionospheric current system. The diffuse aurora, which is excited by high-energy particles of magnetosphere precipitating into the upper atmosphere and impacting with the neutral gas, can respond to the disturbance. Because of the location of Yellow River Station (YRS) in Ny-?lesund, Svalbard is good for the optical observation of dayside aurora. A case of the dayside diffuse aurora was observed by the all-sky imager (ASI) in YRS, which intensively responds to a variety of solar wind dynamic pressure. With the enhancement of the solar wind dynamic pressure, the diffuse aurora on the equatorward of ASI’s field-of-view showed the intensity enhance and the poleward extension on latitude, the geomagnetic environment also showed a corresponding disturbance at the same time. We suggested that the dayside magnetopause is compressed because of the enhancement of the solar wind dynamic pressure. It can result in the enhancement of pitch-angle scatter by wave particle interaction in the magnetosphere. Consequently, the number flux of the high-energy particle scattering the loss-cone and precipitating into the equatorward ionosphere of auroral oval is enhanced, and led the emission increase of dayside diffuse aurora.

Key words: dayside diffuse aurora, interplanetary magnetic field, solar wind dynamic pressure, geomagnetic activity