Impact of magnetic storms on the global TEC distribution

Abstract

Abstract. The study is focused on the analysis of Total Electron Content (TEC) variations during six geomagnetic storms of 10 different intensity: from Dstmin = -46 nT to Dstmin = -223 nT. The values of TEC deviations from its 27-day median value (δTEC) were calculated during the periods of the storms along three meridians: American, Euro-African and AsianAustralian. The following results were obtained. For the majority of the storms almost simultaneous occurrence of δTEC maximums was observed along the Asian-Australian and Euro-African meridians at the beginning of the storm. The transition from weak storm to superstorm (the increase of magnetic activity) almost does not affect the intensity of δTEC 15 maximum. The effect revealed for the American sector during two storms was the movement of the disturbance front from Northern and Southern high latitudes towards the equator with the average velocity of ~ 400 m/s. The seasonal effect was most pronounced at Asian-Australian meridian, less often at Euro-African meridian and was not revealed at American meridian. Sometimes the seasonal effect can penetrate to the opposite hemisphere. The character of averaged δTEC variations for the intense storms was confirmed by GOES satellite data. The behaviour of correlation coefficient (R) between 20 δTEC at three meridians was analyzed for each storm. In general, R>0.5 between δTEC averaged along each meridian. This result is new. The possible reasons for the exceptions (when R < 0.5) were provided: time-shift of δTEC maximum at different latitudes along the American meridian, the complexity of phenomena during the intense storms and discordance in local time of geomagnetic storm beginning at different meridians. Notwithstanding the complex dependence of R on the intensity of magnetic disturbance, in general R decreased with the growth of storm intensity. 25

Performance of the Ionospheric Kappa‐Correction of Radio Occultation Profiles Under Diverse Ionization and Solar Activity Conditions

“…As shown by Blagoveshchensky et al. (2018), sudden changes in the geomagnetic field can lead to a change in the TEC value of up to 67% of its quiet state. A possible way, to assess whether the kappa‐correction accounts for such drastic changes in the geomagnetic field would be a comparison study to the bi‐local correction approach, which includes the strength and the direction of the geomagnetic field (Liu et al., 2020).…”

“…The results of Blagoveshchensky et al. (2018) also show that the responses to sudden changes in the magnetic field are very different for different parts of the Earth. We therefore expect that differences average out globally in a climatological context.…”

Long Short‐Term Memory Neural Network for Ionospheric Total Electron Content Forecasting Over China

“…Previous studies have shown that solar and geomagnetic activities affect TEC variability (Blagoveshchensky et al., 2018; Kumar & Singh, 2010; Purohit et al., 2015; Verkhoglyadova et al., 2013) and that the use of auxiliary solar and geomagnetic activity index data potentially improves prediction performance. Specifically, time‐delayed historical data and current auxiliary data of the solar flux index K p and geomagnetic activity index a p from all selected GPS stations were concatenated and stacked to compose an input sequence for the LSTM layers (“Main Inputs” in Figure 3).…”

Simultaneous Observations of Electromagnetic Ion Cyclotron (EMIC) Waves and Pitch Angle Scattering During a Van Allen Probes Conjunction

“…The 19–22 December 2015 storm was a significant and complex event that has been mentioned in several papers on the effects of space weather. These papers have examined the scintillation of transionospheric radio signals (Chashei et al, 2016; Loucks et al, 2017; Wang et al, 2018; Zakharenkova & Cherniak, 2018), the ionospheric total electron content (TEC) (Blagoveshchensky et al, 2018; Mansilla, 2019), geomagnetically induced currents (GIC) in the Irish power network (Blake et al, 2016), and the response of the magnetosphere as a nonlinear system (Balasis et al, 2018). This storm has also been mentioned in papers using Van Allen Probes data, including a study of impulsive electric fields associated with interplanetary shocks (Zhang et al, 2018), a study of whistler mode chorus with tones that oscillate in frequency (Gao et al, 2017), and a survey of radiation belt enhancements observed by the Van Allen Probes from October 2012 to April 2017 (Boyd et al, 2018).…”