不同行星际磁场条件下极向运动极光结构的多手段联合观测  

MULTI-INSTRUMENT STUDY OF POLEWARD MOVING AURORAL FORMS DURING DIFFERENT INTERPLANETARY MAGNETIC FIELD CONDITIONS

作　　者：邢赞扬[1,2] 杨惠根[2] 韩德胜[2] 吴振森[1] 刘俊明[2] 胡泽骏[2] 张清和[2] 刘勇华[2] 张北辰[2] 胡红桥[2] 

机构地区：[1]西安电子科技大学理学院,陕西西安710071 [2]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

出　　处：《极地研究》2013年第1期35-44,共10页Chinese Journal of Polar Research

基　　金：国家自然科学基金项目(40974083;41031064;41104091;41104090;41274164);海洋公益性行业专项(201005017);中国极地科学战略研究基金项目(20100202;20100203;20120304);南北极环境综合考察与评估专项(CHINARE2012-02-03)资助

摘　　要：利用北极黄河站三波段全天空成像仪(ASI)的高分辨率的地面极光观测数据,联合欧洲非相干散射雷达(EIS-CAT)Svalbard雷达(ESR),超级双子极光雷达网(SuperDARN)雷达等观测,研究了发生在2003年12月22日0900—1010 UT时间段内极区电离层极光和等离子体的变化特征。研究发现在不同行星际磁场(IMF)条件下,黄河站极光ASI均观测到了一系列极向运动极光结构(PMAFs),其特征为极光在赤道向一侧点亮后向高纬扩展。这些PMAFs都伴随有明显的粒子沉降特征,且在IMF北向时该粒子沉降能达到更低的电离层E层区域,而此时这些PMAFs相应位置的高纬电离层出现了一个典型反向对流涡,这是高纬(尾瓣)重联的典型特征之一。这些结果表明北向IMF条件下的这些PMAFs是由高纬重联所产生。在IMF南向时,黄河站观测到的PMAFs可跨越更广的地磁纬度,表明其演化时间亦较长,其相应区域的电离层特征也表明该PMAFs由日侧磁层顶低纬磁重联所产生。In this study we investigate auroral and plasma features in the polar ionosphere under different interplanetary magnetic field （IMF） conditions between 0900 and 1010 UT on 22 December 2003. We use high temporal resolu- tion optical data obtained from three-wavelength all-sky imagers at Yellow River Station （YRS） （78.92°N, 11.93°E） in the Arctic, together with data from the EISCAT Svalbard radar （ESR） and SuperDARN HF radars. A series of poleward-moving auroral forms （PMAFs） are observed to brighten at the equatorward boundary of the day- side auroral oval and then propagate poleward. Simultaneous optical and ESR observations reveal that all of these PMAFs are clearly associated with pulsed plasma precipitations. During northward IMF conditions, the plasma canprecipitate lower, reaching the ionospheric E-region, and there is a reverse convection cell associated with these PMAFs, which is one of the typical signatures in the polar ionosphere of the dayside high-latitude （lobe） reconnec- tion. These results indicate that the PMAFs can be attributed to the high-latitude reconnection. During southward IMF conditions, the PMAFs observed at YRS show a larger latitudinal motion indicating a longer mean lifetime, and the associated ionospheric features indicate that the PMAFs are generated by the dayside magnetopause low-latitude reconnection.

关 键 词：极向运动极光结构 行星际磁场 磁重联 

分 类 号：P353[天文地球—空间物理学]