Ⅱ型射电暴射电增强与太阳高能粒子事件关系的统计  

Statistical analysis of the relationship between type Ⅱ radio enhancement and solar energetic particle event

作　　者：周坤论 丁留贯[1,2,3] 钱天麒 朱聪 王智伟 封莉 Zhou Kun-Lun;Ding Liu-Guan;Qian Tian-Qi;Zhu Cong;Wang Zhi-Wei;Feng Li(Institute of Space Weather,Nanjing University of Information Science and Technology,Nanjing 210044,China;Binjiang College,Nanjing University of Information Science and Technology,Nanjing 210044,China;Key Laboratory of Dark Matter and Space Astronomy,Purple Mountain Observatory,Chinese Academy of Sciences,Nanjing 210008,China;China Polar Research Center,Shanghai 200000,China)

机构地区：[1]南京信息工程大学空间天气研究所,南京210044 [2]南京信息工程大学滨江学院,南京210044 [3]中国科学院暗物质与空间天文重点实验室,南京210008 [4]中国极地研究中心,上海200000

出　　处：《物理学报》2020年第16期340-351,共12页Acta Physica Sinica

基　　金：国家自然科学基金联合基金(批准号:U1731105);江苏省基础研究计划面上项目(批准号:BK20171456);中国科学院暗物质与空间天文重点实验室开放课题;南京信息工程大学滨江学院院级科研课题(2020年);国家重点研发计划(批准号:2018YFC1407304,2018YFF01013706);电波环境特性及模化技术重点实验室基金(批准号:201801003)资助的课题。

摘　　要：本文基于Learmonth等地面台站和Wind/WAVES, STEREO/SWAVES等卫星射电观测资料,筛选了第24个太阳活动周2007年1月至2015年12月期间82个米波-十米百米波(meter-decahectometric, M-DH)、十米-百米波(deca-hectometric, DH)Ⅱ型射电暴事件,其中39个射电增强事件和43个非射电增强事件.研究结果显示:1)射电增强事件的日冕物质抛射(coronal mass ejection, CME)速度、质量、动能和耀斑等级普遍高于无射电增强事件的;无论有无射电增强,产生太阳高能粒子(solar energetic particle, SEP)事件的CME速度、质量和动能均明显大于无SEP事件的CME. 2)特征时间分析显示高能粒子起始释放时间普遍早于射电增强开始时间,由此表明射电增强不是导致高能粒子事件产生的直接原因. 3)无论有无射电增强,SEP事件伴随的Ⅱ型射电暴开始高度略低于无SEP事件的;而Ⅱ型射电暴结束高度,产生SEP的事件明显高于无SEP的事件;伴随射电增强的Ⅱ型射电暴结束高度显著大于无射电增强事件,即表明有射电增强事件中的激波更强且可持续到更高高度. 4)当快速CME完全扫过另一个先行CME时, CME相互作用更易产生射电增强,而是否产生SEP无明显差异.本文结果表明,射电增强是CME激波与其他CME相互作用而增强的表现,增强的激波可能增强粒子加速过程而更易产生大的SEP事件,但射电增强并非产生SEP事件的直接原因.In this paper, we investigated 82 type-Ⅱ radio burst events detected by some ground stations Learmonth,YNAO, and BIRS and spacecraft Wind/WAVES, STEREO/WAVES from January 2007 to December 2015.And we identified 39 events associated with radio enhancement and 43 events without enhancement. We found that: 1) The CME velocity, mass, kinetic energy and flare class with respect to type Ⅱ radio enhancement events were generally higher than that of no enhancement events, and these properties in the solar energetic particle(SEP) events were significantly higher than that no SEP event, regardless of whether radio enhancement or not. 2) As shown in the characteristic time analysis, the initial release time of SEPs is generally earlier than the start time of radio enhancement, so we can the radio enhancement is only as a signature of the shock enhancement rather than the direct generator of SEP events. 3) Whether radio enhancement or not, the onset height of type Ⅱs associated with SEP event is slightly lower than that of event without SEP. For the absence height, the SEP events are significantly higher than the no-SEP events, and that the absence height of enhancement events are also distinctly higher than that non-enhancement events, which reveals that the enhanced CME shock characterized by enhanced radio burst can keep propagating to more higher or further space. 4) When one fast and wide CME fully sweeps over another slow and narrow preceding CME, CME interaction can more easily generate radio enhancement, but no distinctive difference between SEP events and non-SEP events. So the results of this paper reveal that radio enhancement can be regarded as a manifestation of CME shock becoming strong during interacting with other CME, and the enhanced shock can accelerate the particle to generate large SEP events more easily. However, the type Ⅱ radio enhancement is not the direct producer or causer that generate large SEP event.

关 键 词：Ⅱ型射电暴 射电增强 太阳高能粒子 激波增强 

分 类 号：P353[天文地球—空间物理学]