Studies of Periodic Substorms

Massachusetts Institute Of Technology, Cambridge MA

Investigators

Abstract

The quasi-periodic injection of energetic particles into the inner magnetosphere has become one of the most interesting and controversial topics in magnetospheric physics. These events, knows as "sawtooth events" and sometimes as "periodic substorms" occur during geomagnetic storms when the interplanetary magnetic field (IMF) has been southward for a prolonged period. This is a one-year project to examine to what extent the apparent periodic of the phenomena can be related to a driving periodic in the solar wind. If there is no driving periodic in the solar wind it would indicate that the events are driven by some as yet unidentified normal mode of the Earth's magnetosphere. The project will examine energetic particle injections at synchronous orbit to determine which of their characteristics are related to a solar-wind driver and which are better described as arising due to magnetic substorms initiated deeper in the Earth's magnetotail.