TEC evidence for near-equatorial energy deposition by 30 keV electrons in the topside ionosphereстатья
Статья опубликована в высокорейтинговом журнале
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Дата последнего поиска статьи во внешних источниках: 24 декабря 2013 г.
Аннотация:Observations of energetic electrons (10 – 300 keV) by NOAA/POES and DMSP
satellites at heights <1000 km during the period from 1999 to 2010 allowed finding
abnormal intense fluxes of ~10^6 – 10^7 cm-2 s-1 sr-1 for quasi-trapped electrons appearing
within the forbidden zone of low latitudes over the African, Indo-China, and Pacific regions.
Extreme fluxes appeared often in the early morning and persisted for several hours during
the maximum and recovery phase of geomagnetic storms. We analyzed nine storm time
events when extreme electron fluxes first appeared in the Eastern Hemisphere, then drifted
further eastward toward the South-Atlantic Anomaly. Using the electron spectra, we
estimated the possible ionization effect produced by quasi-trapped electrons in the topside
ionosphere. The estimated ionization was found to be large enough to satisfy observed
storm time increases in the ionospheric total electron content (TEC) determined for the same
spatial and temporal ranges from global ionospheric maps. Additionally, extreme fluxes of
quasi-trapped electrons were accompanied by the significant elevation of the low-latitude
F-layer obtained from COSMIC/FORMOSAT-3 radio occultation measurements. We
suggest that the storm time ExB drift of energetic electrons from the inner radiation belt is an important driver of positive ionospheric storms within low-latitude and equatorial regions.