对太阳第21周最强烈活动区的分析

An Analysis on the Strongest Active Regions of Solar Cycle 21st

太阳第２１周实测到３９８６个活动区，以黑子面积、Ｘ射线耀斑指数、１０．７ｃｍ射电爆发及质子事件等四项指数，从中综合评估出ＡＲ３８０４、ＡＲ４４７４等１６个最强烈活动区。与２２周比较，两周都有在时空分布的相对集中性特征。但２１周集中在４个时段，不如２２周在２个时段集中；２１周出现的５个热点，只有南半球在经度８５°前后的热点，与２２周３个热点之一相似；２１周的整体活动水平略低。

A total of 3986 active regions are recorded during the 21st Solar Cycle. We define 16(e. g. AR3804, AR4474)of the active regions as the strongest active regions in terms of 4 indicies —sunspot area, index of the X-Ray flares, 10.7cm radio flux and proton event index. Compared with 22nd Solar Cycle we found that both have the characteristics: for the 21st Solar Cycle, the active regions distribute centrally in the 4 time periods but for the 22nd in 2 periods; for the 5“hot spots ”only those lie at the neighboring of 85° latitude in the southern hemisphere are similar to one of the 3 hot spots of the 22nd Solar Cycle. Generally, the level of activity in the 21st Solar Cycle is lower than that in the 22nd Solar Cycle, especially in the respect of X-ray and proton events.