Discovery of a low-latitude ionospheric trough associated with the inner radiation belt

Abstract The dynamics of ionospheric troughs that developed during a great geomagnetic storm on 11–13 April 2001 are studied using measurements electron density obtained by the CHAMP satellite at an altitude 410–465 km. Subauroral, mid-latitude and low-latitude were observed nighttime, sometimes simultaneously. subauroral trough is usually defined as main trough, whereas associated with magnetospheric ring current. It appeared beginning recovery phase around latitudes 40°–45° GMLat (L = 1.7–2.0) existed for long period time throughout late residual current 50°–55° ~ 2.4–3.0). For first time, was revealed. 34°–45° 1.45–2.00) in association precipitation energetic particles from inner radiation belt.