一种基于白谱法的电离层天气扰动指数

基于一种电离层扰动提取方法——白谱法，利用IGS提供的电离层TEC网格数据，获得电离层J_s指数、J_r指数和J_p指数，分别反映单站、纬度圈（沿经度积分）及行星际尺度下的电离层天气扰动状态.在2015年3月的一次磁暴过程中，J_s指数、J_r指数及J_p指数均很好地反映出电离层响应地磁暴的过程，磁暴前后J_p指数与Dst指数相关系数达到-0.72；J_s图从二维角度很好地表征了电离层天气的扰动过程.在此基础上，统计分析了2011——2014年J_p指数与Dst指数的相关性，结果表明:限定J_p≥2，J_p指数与对应时间Dst指数的相关系数为-0.67；限定J_p≥3，二者相关系数更高，达到-0.87.通过分析不同J_p指数阈值下不同等级磁暴的次数，发现J_p指数可以很好地反映磁暴下的电离层整体扰动，为指示电离层天气状态提供了可能的参数. 

Ionospheric Weather Disturbance Indices Based on Spectral Whitening

A Spectral Whitening Method (SWM) is introduced and applied in the study of ionospheric weather disturbances to calculate J_s, J_r and J_p indices on the basis of Total Electron Content (TEC) data provided by IGS. These indices can reflect the disturbances of ionospheric weather of single station, latitude circle (integral along longitude) and the whole planet separately. During a geomagnetic storm in March 2015, all three indices well reflect the ionospheric disturbances. The correlation coefficient between J_p and Dst indices reaches -0.72, and the 2D images of ionospheric disturbances can be well captured by J_s map. The correlation coefficient between J_p index and Dst index, from 2011 to 2014, reaches -0.67 if J_p is greater than or equal to 2, and the correlation coefficient can reach -0.87 if J_p is greater than or equal to 3. By analyzing the frequencies of different levels of geomagnetic storms under different threshold values of J_p index, the results suggest that J_p index, as a possible characterization parameter of ionospheric weather condition, can well reflect planetary ionospheric disturbances during geomagnetic storms.