Synchronous orbit relativistic electron flux one week dropout

Abstract:

A phenomena that >2 MeV electron flux dropped and last 6 days had been discovered by multi satellites such as Chinese FY series, Russian Metor-II and American GOES. During the period from 1 February to 6 February 2016, the >2 MeV electron flux from FY2G satellite had declined by more than two orders of magnitude to background levels and remained at the reduced levels for nearly one week . At the time of the flux dropout, the interplanetary conditions had the characteristics with around 400km/s low solar wind speed and less than 10/cc ion density. However 1 February full day Bz was <-5 nT and 3 February more than 10 hour Bz was <-5 nT , they had led to successively two small geomagnetic storms (reaching -50 nT) occurring on 1 February and 3 February respectively. The special response of the Earth's synchronous orbit environment to this type of solar driver had been revealed by multi spacecraft’s observation and possible mechanism about the dropout have been also interpreted by some theoretical description. It is demonstrated that there is a one-week high safety period to various space activities near the Earth's synchronous orbit.