太阳活动峰年和谷年期间黑子群与耀斑的统计分析

Statistical analysis of sunspot groups and flares for solar maximum and minimum

基于NOAA/SWPC公布的太阳活动数据,我们选取第24太阳活动峰年附近的12个连续月份(2011年7月至2012年6月)和第23太阳活动周谷年附近的12个连续月份(2005年7月至2006年6月),统计了这两段时间中太阳黑子群和耀斑的活动规律,并根据时间、黑子群分布纬度、寿命和磁场类型等对峰年和谷年进行了详细分析和比较,主要结论如下所述.(1)黑子群数随时间的变化在峰年和谷年均比较随机,峰年期间黑子数比谷年增多1.5倍左右.耀斑爆发与黑子群活动具有良好的相关性,但峰年期间存在某个月份耀斑数很少的现象,而谷年期间存在某个月份耀斑数集中增多的现象.(2)无论峰年还是谷年,δ类型黑子群的耀斑产率(耀斑总数与黑子群总数之比)最大,但β型黑子群产生的耀斑爆发最多.耀斑产率与磁场类型有密切关系,但与其所处太阳活动周中的阶段无关.(3)黑子群和耀斑的纬度分布的南北不对称性,以X级耀斑最为显著.峰年较谷年的耀斑数增加主要集中在C级和M级.(4)耀斑产率同黑子群寿命具有良好的相关性,但黑子群的数目同它们的寿命之间没有明显的规律.

Based on the NOAA/SWPC data, by choosing two separative periods with successive 12 months, that is, 2005 July-2006 June （during the solar minimum） and 2011 July-2012 June （during the solar maximum）, we analyze the activity of flares and compare the statistical results between the two periods for studying their evolution with time, sunspot distribution, sunspot lifetime and magnetic field types. The main conclusions are： （1） The time variation of sunspot groups number is random for both the solar minimum and maximum periods. The sunspot number during the solar maximum is about 1.5 times larger than during the solar minimum. The flare number shows good correlation with the sunspot group number. During solar maximum there may be very few flares for some months, while during solar minimum there can be plenty of flares for some months, indicating the importance of keeping monitoring for solar activities even during the solar minimum period. （2） The 6-sunspot groups have the highest flare productivity （the ratio of flare amount to sunspot group number） for both solar minimum and maximum, while the E-sunspot groups have produced the most flares. The flare productivity of sunspot groups has close relation with magnetic field type, and it has no obvious relation with the state of solar cycle. （3） There is serious asymmetry in the distribution for flares, especially for X-class flares. The increase of the flares number from solar minimum to maximum is mainly caused by C- and M-cIass flares. （4） The number of sunspot groups has no obvious correlation with their lifetime, while the flare productivity shows well correlation with sunspot lifetime for all periods.