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200136
出 处:《空间科学学报》2021年第3期355-367,共13页Chinese Journal of Space Science
基 金:国家自然科学基金天文联合基金项目(U1731105);江苏省基础研究计划面上项目(BK20171456);中国科学院暗物质与空间天文重点实验室开放课题;国家重点研发计划项目(2018YFC1407304,2018YFF01013706)共同资助
摘 要:基于多卫星联合观测数据,筛选了2006年12月至2017年10月期间122个太阳高能粒子(SEP)事件及其伴随的日冕物质抛射(CME),分析了SEP事件属性随相对经度的变化、与CME属性之间相关性的经向分布以及与Fe/O比值的关联.研究结果显示:低Fe/O类事件的峰值通量I_(p)通常更高,伴随CME更大,但通量上升速度较慢,且其D_(u)(持续时间)和I_(p)与CME速度呈现更强的相关性;SEP特征时间T_(o)(CME爆发至SEP事件爆发)与T_(R)(SEP事件爆发至半峰值)随相对经度增加而增大,D_(u)与I_P随相对经度增加而减小,通量上升斜率K在±90°范围内自东向西递减;SEP事件属性与伴随CME属性的相关性随相对经度的改变有明显变化,在磁连接好的位置,T_(o)与CME速度等属性呈现负相关,T_(R)与CME速度等属性呈现正相关,D_(u),I_(p)与CME速度之间的相关性更强.研究结果进一步表明,SEP事件观测属性既与CME参数相关,同时又具有很强的经度依赖性,在磁连接越好的位置卫星观测到的SEP事件强度越高,SEP观测参数受CME的影响越大,这对大型SEP事件的预报很有意义.此外,高Fe/O类SEP事件与CME相关性的减弱暗示了耀斑加速、种子粒子源等因素的影响.Using the observations from multi-points spacecraft,e..g.,SOHO and STEREO,122 SEP events and associated CMEs during the 24 th solar cycle from December 2006 to October 2017 are selected.The longitudinal distributions of SEP characteristics and their relationship with CMEs properties are analyzed,as well as the relation with the event-integrated Fe/O ratio.Results are shown as follows:Large SEP events usually have a lower Fe/O ratio,while those events with high Fe/O have lower CME velocity,mass and kinetic energy,but have faster flux rising speed.The duration D_(u) and peak flux I_(p) of SEP correlate well with the associated CME velocity positively(correlation coefficient,CC:0.50 and 0.57).Comparing to the events with a high Fe/O ratio,the events with low Fe/O obviously have much higher correlation coefficients for D_(u) and I_(p) with CME.The characteristic time T_(O) and T_(R) of SEPs generally increases with the raising of relative longitude,while D_(u) and I_(p) decrease distinctly with the raising of relative longitude.And the slope K of the SEPs flux enhancing in the onset phase seems to decrease from the east(-90°)to west(90°)relative to the source region.T_(O) shows a negative correlation with CME velocity,mass and kinetic energy in the magnetic well-connected points,while there is no distinct correlation in other poor-connected points.Meanwhile,T_(R) has a positive correlation with CME only in the relative longitude range of[-30°,+30°].D_(u) and I_(p) have a stronger correlation with CME velocity in the well-connected condition(CC:0.60 and 0.75 respectively)than others(0.46 and 0.56).The conclusion reveals that the detection of SEP event and its time profile evolution is not only affected by the associated CME,but also controlled by the relative longitude between the magnetic foot point and the solar eruption source,and for the well-connected points,the detectable SEP event has more high intensity and good positive correlation with its associated CME,which is very important for the space weather pred
分 类 号:P353[天文地球—空间物理学]
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