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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3 R s, R s为太阳半径), 且能维持到很高的高度(如大于30 R 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 ( E k) 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-DH-KM 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 R s, R s: solar radius), and are sustained to a much larger height (such as > 30 R s). 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 that the generation of SEP events is greatly related to the sub-types and characteristics of type II radio bursts. The higher the starting frequencies and the lower the ending frequencies of type II radio bursts, such as M-DH-KM type II bursts, of which the CME drives to forming shock waves at a very low height and propagates to a very large height, the longer the duration of the shock, the longer the time it takes to accelerate the particles, and the greater the probability of SEP events (especially large SEP events) is.
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事件类型 G1 G2 G3 G4 G5 All IIs事件数 107 32 36 38 60 273 无SEP事件数 80 26 20 22 16 164 SEP事件数 27 6 16 16 44 109 SEP事件占比/% 25 19 44 42 73 40 大SEP事件数 13 3 12 13 40 81 大SEP事件占比/% 12 9 33 34 67 30 SEP事件强度均值 0.53 0.02 0.49 4.89 38.74 16.41 SEP事件强度中值 0.01 0.01 0.2 0.24 0.53 0.09 大SEP事件强度均值 1.09 0.04 0.65 6.02 42.62 22.28 大SEP事件强度中值 0.13 0.02 0.33 0.25 0.6 0.34 
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类型 T1/min T2/min 均值 中值 均值 中值 G1: M IIs only 14 10 26 19 G2: DH IIs only 38 18 66 33 G3: M-DH IIs 19 16 32 27 G4: DH-KM IIs 35 23 70 52 G5: M-DH-KM IIs 46 22 73 49 下载:
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