基于多日地磁场数据的K指数现报  

K-indices nowcast based on digital magnetogram data from the previous 27-day period

作　　者：张晓芳 刘松涛 符养 周率[2,4] 

机构地区：[1]北京市5111信箱,北京100094 [2]航天飞行动力学技术重点实验室,北京100094 [3]北京应用气象研究所,北京100029 [4]北京航天飞行控制中心,北京100094

出　　处：《地球物理学进展》2014年第5期2120-2127,共8页Progress in Geophysics

基　　金：航天飞行动力学技术重点实验室开放基金(2012afdl034)项目;国家重点基础研究发展计划973(2012CB825606)项目联合资助

摘　　要：基于连续27天地磁平静时地磁场H分量提取磁场规则日变化曲线,对2011-2013年佘山和北京台的地磁K指数进行现报,将计算结果（Know）与中国地磁台网公布的K指数（Kobs）以及FMI方法结果（Kfmi）、Kp指数进行了比较.去除∣Kobs-Kp∣≥4数据后的分析结果表明：Know与Kobs、Kfmi有较好的一致性,与Kobs、Kfmi完全吻合的比例分别可达53.5%和63.8%,序列差值在1个标度之内比例为94.7%和98.1%;现报方法所计算的K指数能给出即使是轻微程度的地磁扰动,在5-8高K区Know与Kobs、Kfmi有很好的吻合性,由于忽略了磁场日变化,0-2 K区的Know结果偏高;与佘山台和北京台的K指数相比,Kp处于0-1低K区的频率远高于K指数,对应Kp≥5的佘山台98.3%和北京台96.6%的Kobs小于等于Kp指数;佘山台Kobs指数与同时刻加权平均的Kp指数吻合较好,北京台的Kobs、Kfmi和Know高于Kp,利用修正后三小时扰幅计算的北京台K指数与Kp吻合度提高.Obtaining the solar regular variation（SR）of the geomagnetic field curve based on the H component of digital magnetogram measurements from those quiet geomagnetic days only（i.e.from only those days when K〈3）during the previous 27-day period,K-indices were scaled in real time for the Sheshan and Beijing station during 2011-2013.Based on data of ∣ Kobs-Kp∣ 〈4,the nowcast-estimated K-indices（Know）were compared with the K-indices from geomagnetic network of China（Kobs）and those scaled by FMI method（Kfmi）,and with the Kp-indices.The statistical results show that the nowcast K-indices present good correlation with Kobs and Kfmi.53.5% of the nowcast-estimated K-indices are in agreement with the Kobs-indices,94.7% differing not more than one unit,and 63.8% of the Know-indices are in agreement with the Kfmi-indices,98.1% differing not more than one unit.The nowcast K-indices can be sensitive to geomagnetic disturbances and shows little difference with the Kfmi-indices and the Know-indices when Kobs≥5,while the Know-indices are a little bigger than the Kfmi-indices and the Know-indices when Kobs≤2.Frequency of the Kp-indices which are 0-1scale is much higher than that of the Kfmi-indices and the Know-indices,while 98.3% of the Kobs-indices for the Sheshan observatory and 96.5% for the Beijing observatory are no higher than the simultaneous Kp-indices when Kp ≥5.The Kobs-indices of Sheshan observatory are in good agreement with the simultaneous weighted average Kp.The Kobs-indices of Beijing observatory are higher than Kp, while the Kobs-indices calculated based on the modified K-scale are in better agreement with the simultaneous weighted average Kp.

关 键 词：K指数现报 规则日变化SR 3小时扰幅 FMI方法 KP指数 

分 类 号：P318[天文地球—固体地球物理学]