两冕流间的对称径向膨胀日冕物质抛射事件  

RADIAL EXPANSION OF A SYMMETRICAL CME BETWEEN TWO CORONAL STREAMERS

作　　者：章公亮[1] 

机构地区：[1]中国科学院空间科学与应用研究中心

出　　处：《空间科学学报》1995年第4期253-262,共10页Chinese Journal of Space Science

基　　金：国家自然科学基金

摘　　要：本文讨论了发生在冕流对之间的１９８０年５月６日日冕物质抛射事件．提出了一种描述事件外环运动的经验模型，把环的观测外形表达为在运动坐标系中的Ｃａｓｓｉｎｉ函数．环的发展过程分为两个阶段：在前一阶段，外环处于冕流对盔状结构之间，事件的发展以角宽度膨胀为主，其对称轴从赤道向北纬方向移动；径向膨胀和上升速度较低，加速效应明显．在后一阶段，外环越过冕流盔状结构所在高度，角膨胀趋于停止；运动接近于等角宽度和纯径向匀速的膨胀和上升运动．当外环向外运动时，其顶部和几何中心的高度均随时间而增加，但其底部高度基本上保持不变．根据上述观测特征，讨论了事件形成的可能机制．The CME event on May 6,1980,occurring between a pair of coronal streamers,is discussed in this paper.An empirical kinematical model is proposed for describing the motion of outer loop of the event,n which the observed profile of loop is fitted in terms of the Cassini function in a moving coordinate system.The development of the loop can be distinguished into two different phases.During the first phase,when the loop lay between the helmet structures of streamer pair,the development of event is dominated by expansion of angular width with the asymmetrical axis shifting to northern latitudes;the speed of radial expansion and outward motion were rather low with remarkable acceleration.During the second phase,when the outer loop moved beyond the height of helmet structure of coronal streamer,the angular expansion ceased;the motion approached to an expansion and lift mainly in the radial direction with uniform speed and invariable angular width.As the loop moved outward,both the top and center heights increased with time, however,the bottom remained nearly fixed.Based on the above observational characteristics,a possible mechanism is put forward for the formation of the event.

关 键 词：日冕物质抛射 爆发日珥 冕流 

分 类 号：P182.62[天文地球—天文学]