A new pair of indices to describe the relationship between ionospheric disturbances and geomagnetic activity

Abstract

In this paper, a new ionospheric index pair-the single-station index (Js) and the planetary index (Jp), which describe ionospheric disturbances-is constructed using the spectral-whitening method. Observations covering more than 30 years and obtained from 21 ionosonde stations widely distributed across middle-and low-latitude areas are used in the study. Variations in the Js index at all stations generally follow the variation of the geomagnetic Dst index during periods of strong to moderate geomagnetic activity. Nevertheless, the inertial response of Js to weak geomagnetic activity results in a weak correlation between Js and Dst. The extrema of Js and Dst during the same geomagnetic activity period have a much higher correlation coefficient, since they avoid the delaying effect of the ionospheric response to geomagnetic activity. To smooth out local differences among ionospheric disturbances, the Jp index was defined as the means of all Js indices and so describes ionospheric disturbances at the planetary scale. The Jp index is significantly correlated to the Dst index, and the correlation coefficient between the extrema of Jp and Dst is up to À0.8. This correlation remains robust when the data set length varies, and data from approximately 10 stations are sufficient to derive a reasonable estimate of Jp. The quantitative relationship between Jp and Dst can be used to reproduce Jp by adopting Dst as the precursor, and this raises the possibility of predicting planetary ionospheric disturbances based on geomagnetic activity.

Study on the relationship between the residual 27 day quasiperiodicity and ionospheric Q disturbances

“…The SWM has been shown to be a more effective method of obtaining the ionospheric disturbance related to geomagnetic activity by Wang et al []. Based on the ionospheric disturbance, Chen et al [] constructed a pair of ionospheric indices that are largely independent of solar activity. As the SWM weakens signals at a range of typical periods in the ionosphere, the effect of QP in the R f o F 2 ‐SWM is also very weak, so R f o F 2 ‐SWM is suitable as a control study method to test the contribution of QP to Q disturbance.…”

New understanding achieved from 2 years of Chinese ionospheric investigations

“…The disturbances identified by the SWM have a Gaussian-type distribution, which simplifies further statistical analysis by virtue of the well-known characteristics of the Gaussiantype distributions, and also simplifies the comparisons of the disturbances at different times. Chen et al [14] introduced the single-station index Js and the planetary index Jp to measure the ionospheric state. The Js index describes the local ionospheric variations well, while the Jp index captures the overall features of the ionospheric variations.…”

Improvement of a Deep Learning Algorithm for Total Electron Content Maps: Image Completion

“…The lack of global data coverage is also a common problem to other areas of geophysics. To address this problem, various tailored signal filtering, data interpolation, assimilation, and machine learning methods have been proposed with considerable success (Bortnik et al, 2016;Chen et al, 2014Chen et al, , 2015Hajj et al, 2004;Hernández-Pajares et al, 2009;McGranaghan et al, 2017;Orús et al, 2005;Wang et al, 2014;Zhang et al, 2017). The International Global Navigation Satellite System (GNSS) Service (IGS) Ionosphere Working Group has been established in 1998 to provide reliable vertical TEC maps for space weather events, empirical modeling, and navigation improvement (Hernández-Pajares et al, 2009).…”