SMY和第21太阳周期间地磁及太阳活动特点的分析

本文比较第17—21太阳周黑子数、地磁A_p指数、各周极大年≥2级耀斑数、磁暴数及第一、二、三大磁暴情况;分析了≥2级耀斑数及磁暴的分布。21周3级耀斑对应磁暴比例低于19、20周,Ⅳ型及米波射电爆发是产生磁暴的重要条件。进一步分析了21周最大磁暴、最大射电爆发引起的磁暴,最严重的电离层短波通讯干扰及有明亮物质抛射的大耀斑、双带大耀斑引起的磁暴等典型例子。最后对SMY期间22个无黑子耀斑作了分析,它们可能引起中小幅度的磁暴。 

THE ANALYSIS OF GEOMAGNETIC AND SOLAR ACTIVITIES DURING SMY AND TWENTY FIRST SOLAR CYCLE

This paper compares sunspots,Geomagnetic Ap indexes,numbers of ≥2 solar flares,magnetic storms and first,second and third large magnetic storms every solar cycle during 17th-21st solar cycle.The result is in agreement with the prediction of the first writer for geomagnetic maximum of 21st solar cycle.The geomagnetic activity during the 21st solar cycle is higher.This paper analysis of the numbers of ≥2 solar flares and distributionof magnetic storms has been made.Percentage of magnetic storms resulted by 3 solar flares is lower than 19,20 cycle.Type IVand metre wave radio burst are considered to be important conditions to produce magnetic storms.Some typical example of the largest magnetic storms,the largest radio burst resulting magnetic storms,the most severe short wave communication disturbance in ionosphere and magnetic storms resulted by the large solar flare with bright mass ejection and two-ribbon flares are also given.In the end an analysis has been made on the 22 spotless flares during SMY (Solar Maximum Year).There spotless flares may result medium and small magnetic storms.