地磁活动K指数自动计算FMI方法的改进

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K_p约0.5个单位、个别日期S_R计算错误、相邻日期S_R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.

An improved FMI method of deriving K indices

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 S_R on several individual days, steps between S_R and the next day S_R. 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.