太阳射电米波爆发与日冕物质喷射

Solar Radio Meter Burst and Coronal Mass Ejections

利用云南天文台声光频谱仪观测到的一次特殊的太阳射电米波爆发 ,与对应的光学活动及相关事件 ,我们探讨了 1 991年 6月

A particular solar radio metric wave burst was observed by using the Acousto-Optical Spectrograph in Yunnan Observatory.This burst was related to the optical activity events on June 7,1991.The coronal mass ejection processes in terms of the radio and the optical are investigated in this paper. At 011447UT and 024020UT June 7,1991,Yunnan Observatory recorded several metric spikes and the type-Ⅲ bursts from 230 to 300MHz.It is shown that as the frequency decreased the peak fluxes of the bursts decreased as well as the duration decreased from 3.4s to 2.3s.The X-ray/Hα flare corresponding to these bursts began at 0013UT,maximumed at 0052UT and ended at 0452UT.After the Hα flare took place,shock waves threw the flare mass out to about 70,00km away in the traverse field direction. Consequently,a much clear vision of the events on June 7,1991 is obtained.It was produced in AR6659 that was among the most violent active regions in 22 nd Maximum.In such an active region,new magnetic flux continuously floated out of the photosphere and caused the interaction among current loops,thus produced the quiet prominence eruption and the active prominence eruption as well as the CME.The prominence eruption and CME thereafter generated various radio bursts,such as microwave bursts,metric-wave spikes and the type Ⅲ radiation,metric/decametric-wave type Ⅳ and type Ⅲ bursts.Among the radio bursts,the microwave type Ⅳ,type Ⅱ and interplanetary type Ⅱ bursts are caused by the energetic electrons and therefore they reflect the accelerating process of protons.The post-eruption phase in the microwave burst implies that there is possibly particle acceleration process driven by the released energy of the reconnection in the current sheet that is produced by the interaction between current loops and so does the type Ⅳ burst.In addition,the shock waves that appear accompanying the type Ⅱ busts,especially the interplanetary type Ⅱ bursts are an effective mechanism to accelerate protons from 1MeV-to-20MeV-high energy.Therefore the high-speed CME is the effective mechanism of the energetic proton events and the geomagnetic storms.Although the CME is the most important mechanism of the energetic proton events,an actual proton event is caused usually by several accelerating mechanisms that appear in the active region,including the proton acceleration by the burst wave in the great impulsive phase(radio burst).