Ⅱ型射电暴分类及其与太阳高能粒子事件的关系  

Statistical analysis of characteristics of classified type Ⅱ radio bursts and their associated solar energetic particle events

作　　者：朱聪 丁留贯[1,2,3] 周坤论 钱天麒 Zhu Cong;Ding Liu-Guan;Zhou Kun-Lun;Qian Tian-Qi(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,Chinese Academy of Sciences,Nanjing 210008,China;Guangxi Meteorological Center of Technology and Equipment,Nanning 530022,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]广西区气象技术装备中心,南宁530022

出　　处：《物理学报》2021年第9期432-445,共14页Acta Physica Sinica

基　　金：国家自然科学基金天文联合基金(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)资助的课题。

摘　　要：基于Wind, STEREO等卫星联合观测资料,选取第24太阳活动周2010年1月至2018年3月共计273个Ⅱ型射电暴事件,按起始-结束频率对事件进行分类,统计分析各类Ⅱ型射电暴观测特性差异及其伴随的日冕物质抛射(coronal mass ejection, CME)与太阳高能粒子(solar energetic particle, SEP)事件之间的关联.研究结果显示:1)每一类Ⅱ型射电暴事件中, SEP事件对应的CME角宽、速度、质量、动能及耀斑等级均普遍大于不产生SEP的事件,表明SEP事件的产生需要快速大角宽且高能的CME;2)相比从DH波段开始的Ⅱ型射电暴,从米波段开始的Ⅱ型射电暴伴随大SEP事件的比例更高,多频段Ⅱ型射电暴事件比单频段事件更容易产生SEP事件,其中M-DH-KM Ⅱ型射电暴伴随SEP事件比例最高(73%), DH Ⅱs only类最低(19%);3)同一类Ⅱ型射电暴中,有SEP事件产生的Ⅱ型射电暴比无SEP的事件具有更高的起始频率(更低的激波形成高度)、更低的结束频率(更高的结束高度)、以及更长的持续时间,容易产生SEP事件(尤其是大型SEP事件)的日冕激波普遍在较低高度开始形成(如小于3R_s, R_s为太阳半径),且能维持到很高的高度(如大于30R_s);4) Ⅱ型射电暴持续时间和结束频率呈很强的负相关(cc=–0.93),产生SEP事件的比例随Ⅱ型射电暴持续时间增加而明显增大,随结束频率增加而明显降低,且很大程度上取决于CME的速度等参数.本文结果进一步表明, SEP事件产生与否与Ⅱ型射电暴种类及特性明显相关, Ⅱ型射电暴起始频率越高、结束频率越低,如M-DH-KM Ⅱ型射电暴,其CME在很低高度驱动形成激波并传播至很高高度,激波持续时间越长,加速粒子时间越长,产生SEP事件(尤其是大SEP事件)的概率也就越大.In this paper, we investigate 273 type Ⅱ radio burst events detected by Wind, STEREO spacecraft from January 2010 to March 2018 during the 24th solar cycle. We classify all events as five groups or sub-types according to their starting and ending frequencies, and then analyze the observed characteristics of each group of type Ⅱ radio bursts and the correlation between the occurrence of solar energetic particle(SEP) events and the associated coronal mass ejection(CME) or type Ⅱ radio bursts. What we find is as follows. 1) In each group of type Ⅱ radio burst events, the CME speed(v), width(WD), mass(m), and kinetic energy(Ek) associated with SEP events are generally greater than those with no SEP events, indicating that the generation of SEP events requires a fast and wide energetic CME eruption. 2) Compared with type Ⅱ radio bursts starting from the DH band, type Ⅱ radio bursts starting from the metric band have a higher proportion of large SEP events.Multi-band type Ⅱ radio bursts are more likely to produce SEP events than single-band events, where M-DHKM type Ⅱ bursts have the highest proportion of SEP events(73%), and the DH Ⅱs only have the lowest one(19%). 3) In each kind of type Ⅱ radio bursts, the type Ⅱs with SEP events usually have higher starting frequencies(lower shock forming heights), lower ending frequencies(higher ending heights) and longer durations than those with no SEP events;coronal shock waves that are easy to produce SEP events(especially large SEP events) generally begin to form at a lower height(such as < 3 Rs, Rs: solar radius), and are sustained to a much larger height(such as > 30 Rs). 4) There exists a strong negative correlation between the duration and the ending frequency of type Ⅱ radio burst(cc = –0.93). The proportion of SEP events increases with the increase of the duration of type Ⅱ radio burst, and decreases with the increase of the ending frequency, which largely depends on the CME speed and other properties. The results of this paper further show t

关 键 词：Ⅱ型射电暴 太阳高能粒子 日冕物质抛射 激波 

分 类 号：P353[天文地球—空间物理学]