地磁活动K指数自动计算FMI方法的改进

摘要

The differences between the K indices derived with the FMI Method (V1.0) and the Kp Indices were analyzed,four problems were found such as discrete K1 and K8 among different observatories,K indices about 0.5 larger than Kp indices,wrong SR on several individual days,steps between SR and the next day SR.In order to resolve the above mentioned problems,we improved the FMI method of deriving K Indices.The K indices derived with the improved FMI Method were compared with the Kp indices,the K indices derived with the original FMI Method and other methods as well,it was found that the K indices derived with the improved FMI Method were closer to the Kp indices and the K indices derived with other methods than the original FMI Method.%将Kp指数与国际地磁学与高空物理学协会(International Association of Geomagnetism and Aeronomy,下文简称IAGA)推荐的FMI方法(V1.0)计算的K值对比分析后发现,二者的差值在中国区域内出现“不同台站之间K1～K8两头离散、K值整体高出Kp约0.5个单位、个别日期SR计算错误、相邻日期SR频繁出现跨天台阶”现象.针对这些现象,分析了可能产生的原因,并对原FMI算法进行了四处改进.用改进后的FMI算法计算了全球8个台站、中国5个台站在2003 2005年和2009年共4年的K指数数据,并将计算结果分别与Kp指数以及这些台站用其他方法计算的K值进行一致性比较,发现改进后的计算结果与二者更为接近,说明本文对FMI方法的改进是有效的.