1996-2002年太阳耀斑的统计分析

分析了1996-2002年南北半球的太阳黑子相对数和南北半球太阳X射线耀斑级别(简称Imp)≥M1．0的太阳X射线耀斑的特征和不对称性．分析结果表明，南北半球的太阳耀斑活动的程度交替上升，在2001年7月以前北半球的太阳耀斑活动强于南半球，2001年7月开始耀斑活动逐渐以南半球为主．本文还逐月分析了1996—2001年南北半球的耀斑指数．2000年7月为第23周太阳指数最大的一个月，与第23周太阳黑子相对数最大月均值吻合．

THE STATISTICAL ANALYSIS OF SOLAR FLARES DURING THE INTERVAL 1996-2002

Solar flares are believed to result from the sudden release of energy stored in magnetic field. In this paper the X-ray solar flares with importance greater than and equal to M1.0 occurred from 1996 to 2002 on the South and North of the solar disk are investigated. The results show that the intensity of the solar flare activities occurred in the Northern and Southern hemisphere is different. As a whole, the solar flare activities in north hemisphere are more intense than that in the south hemisphere during the interval form 1996 to July 2001, while the situation is contrary from August 2001 to 2002. The period of the most intense solar activities for Solar Cycles 23 is July 2000. The solar flare activities in November 1999, March 2000, March and April 2001, September to December 2001 and July to August 2002 are also very intensive. The solar flare index for the interval from 1996-2001 is also investigated. The result shows that the value of solar flare index of the north hemisphere in July 2000 has the biggest value and very outstanding which means that the solar activities in July 2000 are the most intensive for Solar Cycle 23. This result is consistent with that the monthly sunspot numbers having the bigges value in July 2000 for Solar Cycle 23. Because the biggest value of the smoothed monthly mean sunspot number in Solar Cycle 23 is 120.4 in April 2000, so the monthly mean sunspot numbers can depict the solar activity better than smoothed monthly mean sunspot numbers. Now we can't judge which hemisphere's solar flare activities are more intensive , we will get the answer till the end of the Solar Cycle 23. If we want to really compare the solar activities for Solar Cycle 23 between the two hemispheres, the whole areas of the sunspot, coronal mass ejections, and solar proton events and so on must be compared between two hemispheres.