1932—2018年期间基于 Ap 指数地磁活动的太阳周分布和季节分布  

Solar cycle and seasonal distribution of geomagnetic activities based on Ap indices from 1932 to 2018

作　　者：李琪[1] 朱梅 张学锋[2] 乐贵明[3,4] LI Qi;ZHU Mei;ZHANG XueFeng;LE GuiMing(Institute of Geophysics,China Earthquake Administration,Beijing 100081,China;School of Computer Science,Anhui University of Technology,Ma′anshan Anhui 243032,China;Key Laboratory of Radiometric Calibration and Validation for Environmental Satellites,National Satellite Meteorological Center(National Center for Space Weather),China Meteorological Administration,Beijing 100081,China;Innovation Center for FengYun Meteorological Satellite(FYSIC),Beijing 100081,China)

机构地区：[1]中国地震局地球物理研究所,北京100081 [2]安徽工业大学计算机学院,安徽马鞍山243032 [3]中国气象局空间天气重点开放实验室/国家卫星气象中心(国家空间天气监测预警中心),北京100081 [4]许健民气象卫星创新中心,北京100081

出　　处：《地球物理学报》2022年第12期4593-4601,共9页Chinese Journal of Geophysics

基　　金：国家自然科学基金面上项目(41774085)资助.

摘　　要：我们统计分析了1932—2018年期间Ap指数表征的地磁活动的太阳周分布和季节分布.通过分析,我们发现一个太阳活动周每天Ap指数的总和与太阳活动周的幅度具有很好的相关性.太阳活动周最大的Ap值与太阳活动周的幅度相关性比较好.通过拟合,我们得到Ap指数的分布函数为f(Ap)=139.5 e^(-0.2758Ap)+66.2 e^(-0.004377Ap).为了研究Ap≥25事件的太阳周分布和季节分布特征,我们把Ap指数分成了四个范围,即25≤Ap<50,50≤Ap<75,75≤Ap<100,100≤Ap.太阳活动周的研究发现,对于25≤Ap<50,50≤Ap<75,75≤Ap<100,100≤Ap的地磁活动,出现在太阳活动周上升段的比例分别为26.5%、28%、29.1%和31.5%,出现在太阳活动周下降段的比例分别为73.5%、72%、70.9%和69.5%.这表明地磁活动越弱的事件,出现在太阳活动周下降段的比例越高,反之就越低.对于25≤Ap<50,50≤Ap<75,75≤Ap<100,100≤Ap的地磁活动出现在太阳活动峰年附近的比例分别为56.0%、64.9%、65.9%和82.7%.这表明Ap值越大的事件,出现在太阳活动周峰年附近的比例越高.需要指出的是Ap≥100的事件出现在太阳活动的峰年附近的比率明显高于Ap<100的事件.季节分布的研究发现,四个范围内的Ap指数都具有明显的季节分布特征,即春分点和秋分点的地磁活动明显强于其他季节.研究还发现,25≤Ap<50事件在春分点和秋分点的突出程度明显不如Ap≥50的事件.对于Ap≥150的地磁活动事件,3月份、7月份和9月份的数量明显多于其他月份的数量.A statistical study on the properties of solar cycle and seasonal distribution of geomagnetic activities was carried out based on Ap index from 1932 to 2018.It is found that,the sum of Ap index during a solar cycle has a good correlation with the amplitude of the solar cycle(SC).In addition,the largest Ap during a SC is highly correlated with the SC′s.The statistical distribution of the events described by different Ap indices can be well fitted by the function f(Ap)=139.5 e^(-0.2758Ap)+66.2 e^(-0.004377Ap).To study the solar cycle and seasonal distribution of the geomagnetic activities described by Ap≥25,the Ap indices were divided into four subgroups,25≤Ap<50,50≤Ap<75,75≤Ap<100 and 100≤Ap.The analysis of the solar cycle distribution of the four subgroups shows that 26.5%、28%、29.1%and 31.5%of the 25≤Ap<50,50≤Ap<75,75≤Ap<100 and 100≤Ap appeared in the ascending phase,respectively,while 73.5%、72%、70.9%and 69.5%of the 25≤Ap<50,50≤Ap<75,75≤Ap<100 and 100≤Ap appeared in the descending phase,respectively.It shows that the weaker the geomagnetic activities are,the higher proportion it will be for their occurrence in the descending phase of the solar cycle,and vice versa.For the geomagnetic activities with 25≤Ap<50,50≤Ap<75,75≤Ap<100 and 100≤Ap,56.0%、64.9%、65.9%and 82.7%of these geomagnetic activities occurred in the period from two years before to three years after solar maximum,respectively,indicating that the larger the Ap,the higher the ratio of these events concentrated around solar maximum.The ratio of the geomagnetic activities with Ap≥100 appearing around solar maximum is much higher than those with Ap≤100.The monthly numbers of the geomagnetic activities with 25≤Ap<50,50≤Ap<75,75≤Ap<100 and 100≤Ap show that all these geomagnetic activities have significant seasonal distribution,namely that the numbers of these geomagnetic activities in the spring and fall equinoxes were much higher than those in other months.We also found that the prominence of the geo

关 键 词：AP指数 太阳活动周 季节分布 

分 类 号：P353[天文地球—空间物理学]