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

• Main Authors: T. L. Gulyaeva, F. Arikan, I. Stanislawska
• Format: Article
• Language: deu
• Published: Copernicus Publications 2014-11-01
• Series: Advances in Radio Science
• Online Access: http://www.adv-radio-sci.net/12/261/2014/ars-12-261-2014.pdf

The ionospheric <i>W</i> index allows to distinguish state of the ionosphere and plasmasphere from quiet conditions (<i>W</i> = 0 or ±1) to intense storm (<i>W</i> = ±4) ranging the plasma density enhancements (positive phase) or plasma density depletions (negative phase) regarding the quiet ionosphere. The global <i>W</i> index maps are produced for a period 1999–2014 from Global Ionospheric Maps of Total Electron Content, GIM-TEC, designed by Jet Propulson 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 occurrence of planetary ionosphere storm during the magnetic disturbance storm time, Dst, event is evaluated with the superposed epoch analysis for 77 intense storms (Dst ≤ −100 nT) and 230 moderate storms (−100 < Dst ≤ −50 nT) with start time, <i>t</i>₀, defined at Dst storm main phase onset. It is found that the intensity of negative storm, <i>iW</i>^-, exceeds the intensity of positive storm, <i>iW</i>⁺, by 1.5–2 times. An empirical formula of <i>iW</i>⁺ and <i>iW</i>^- in terms of peak Dst is deduced exhibiting an opposite trends of relation of intensity of ionosphere-plasmasphere storm with regard to intensity of Dst storm.