Anomalous electron temperatures above the South American magnetic field anomaly

With an instrument on board the Japanese satellite EXOS-A electron temperatures of more than 1000 K above the “normal” values have been observed in the night-time topside F-region above the geographic region where the total magnetic field is below 20000 nT. Simultaneously enhanced wave emissions on 45 kHz, 2 MHz and 3 MHz were found and an increase in particle precipitation. The observations are described in detail and several mechanism are discussed which can explain the results.