2013 Radiation Belts Workshop: Comprehending, Specifying and Forecasting their Dynamics

Energetic electron flux enhancements during geospace magnetic storms associated with earthward penetration of Pc 4-5 waves?

3 Jul 2013, 12:30

1h

Island of Santorini, Greece (http://en.wikipedia.org/wiki/Santorini)

Poster Waves, Wave-Particle Interactions and Radiation Belt Dynamics Poster Session

Speaker

Ms Marina Georgiou (National Observatory of Athens)

Description

ULF waves with frequencies of a few millihertz have been associated with changes in the flux levels among relativistic electrons comprising the outer zone of the radiation belts. In particular, the fluxes of electrons with energies > 1 MeV in the outer radiation belt increase and decrease during geospace magnetic storms. For all storms studied by Reeves et al. [2003], only about half of them led to increased electron fluxes, one quarter led to decreased the fluxes, and one quarter produced little or no change in the fluxes. We focus on the increase of relativistic electrons observed during a number of magnetic storms by GOES satellites at geosynchronous orbit. To minimise the effects caused by the Earth's magnetic field asymmetries, we apply a statistical reconstruction of the fluxes to a common local time, which is chosen to be noon, a technique proposed by O’Brien et al. [2001]. Complementary, SAMPEX satellite data have been used for broader coverage of the L shells over which the radiation belts extend. Next, we look into multipoint observations from ground-based magnetometer arrays and the characteristics of Pc 4-5 waves during the different phases of the magnetic storms with particular emphasis on the distribution of Pc 4-5 wave power over the L shells that correspond to the radiation belts. With these observations as a starting point, we investigate whether Pc 4-5 wave power penetrates to lower L shells during periods of enhanced relativistic electron fluxes. We discuss, lastly, the implications to wave-particle interaction. The research leading to these results has received funding from the European Community’s Seventh Framework Programme (FP7–SPACE–2010–1) under grant agreement n. 284520 for the MAARBLE (Monitoring, Analyzing and Assessing Radiation Belt Energization and Loss) collaborative research project.