一个多次产生CME的活动区特征分析

THE CHARACTERISTIC ANALYSIS OF AN ACTIVE REGION PRODUCING A NUMBER OF CME'S

1998年 4月 - 5月 82 1 0活动区在日面上接连出现 6次大的爆发活动 ,搜集了这个活动区在整个日面上软X射线曲线 ,射电Ⅱ、Ⅳ型爆发 ,射电日像仪和远紫外观测等资料 ,它的能量积累过程快 ,3次软X射线爆发曲线的时间轮廓有一定的相似性 .发生日冕物质抛射(CME)时 ,它的磁环只是局部开放 ,很快又收拢成一个闭合磁环 ,在一些非热电子的轰击下 ,再度被加热 ,又产生了强烈的X射线爆发和射电Ⅱ、Ⅳ型爆发 .磁环的薄弱处犹如一个活火山口 ,CME容易从此处再次喷发 .找到非热过程与热过程衔接的拐点 ,在SXR时间轮廓曲线上它表现为斜率突变点 .往往有Ⅲ型爆发作为对应的标志 .日冕不同层次上先后出现的Ⅱ型爆发可作为CME出现的有力证据 ,并可作为判断CME运动速度的依据 .

There are 6 successive major burst events in the AR 8210 on the solar disk during April and May, 1998. The data are collected for this active region including the observations on soft X ray, UV, type Ⅱ and Ⅳ radio bursts and radio heliograph. It is found the energy accumulation process is fast and there is similarity among the time profile of the 3 SXR bursts. When CMEs are there on the disk, the magnetic loop opens only partially and soon contracts into closed. The loop is then reheated through bombarding by nonthermal electrons and produces strong X ray bursts, radio types Ⅱ and Ⅳ bursts. The frail part of the loop just like a volcanic crater from where bursts could be taking place again and again. The turning point between a nonthermal process and a thermal process may be found from investigating the time profiles of SXR on which it displays as an catastrophe point of the slope. Furthermaore the existence of type Ⅲ bursts could be a corresponding signature. The appearance of type Ⅱ radio bursts coming from the different coronal layers can be a convincing evidence for the occurring of CMEs and a criterion for judging the speed of CMEs' motion.