Probability of occurrence of planetary ionosphere storms associated with the magnetosphere disturbance storm time events

[摘要] The ionospheric W index allows to distinguish state of the ionosphere andplasmasphere from quiet conditions (W = 0 or ±1) to intense storm (W= ±4) ranging the plasma density enhancements (positive phase) orplasma density depletions (negative phase) regarding the quiet ionosphere.The global W index maps are produced for a period 1999–2014 from GlobalIonospheric Maps of Total Electron Content, GIM-TEC, designed by JetPropulson Laboratory, converted from geographic frame(−87.5:2.5:87.5° in latitude, −180:5:180° in longitude)to geomagnetic frame (−85:5:85° in magnetic latitude,−180:5:180° in magnetic longitude). The probability of occurrenceof planetary ionosphere storm during the magnetic disturbance storm time,Dst, event is evaluated with the superposed epoch analysis for 77 intensestorms (Dst ≤ −100 nT) and 230 moderate storms(−100 < Dst ≤ −50 nT) with start time, t₀, definedat Dst storm main phase onset. It is found that the intensity of negativestorm, iW^-, exceeds the intensity of positive storm, iW⁺, by 1.5–2times. An empirical formula of iW⁺ and iW^- in terms of peak Dst isdeduced exhibiting an opposite trends of relation of intensity ofionosphere-plasmasphere storm with regard to intensity of Dst storm.

[学科分类] 电子、光学、磁材料