Combined Effects of Concurrent Pc5 and Chorus Waves on Relativistic Electron Dynamics Christos Katsavrias 1,2, Ioannis A. Daglis 2,1, Wen Li 3, Stavros.

Combined Effects of Concurrent Pc5 and Chorus Waves

on Relativistic Electron DynamicsChristos Katsavrias1,2, Ioannis A. Daglis2,1,

Wen Li3, Stavros Dimitrakoudis1,2, Marina Georgiou1,2, Constantinos Papadimitriou1,2 and Drew L. Turner4

1. National Observatory of Athens, IAASARS, 15236 Penteli, Greece2. University of Athens, Department of Physics, 15784 Athens, Greece

3. Department of Atmospheric and Oceanic Sciences, UCLA, Los Angeles, California, USA.

4. The Aerospace Corporation, El Segundo, California, USA

EGU General Assembly, 12 - 17 April 2015, Vienna, Austria.

This work has been supported by:

FP7-Space MAARBLE project

Hellenic National Network for Space Weather Research


Brief introduction Data and analysis Selected Events Results Conclusions

Outline


Assess the contribution of various mechanisms to the variability of the outer Radiation Belt (e.g. inward diffusion, in-situ acceleration via wave-particle interactions, precipitation into atmosphere, magnetopause shadowing combined with outward diffusion) .

Investigate the impact of ICMEs on the dynamics of relativistic electrons.

Motivation – Goal


Note: In most cases/events the maximum compression of

the magnetopause reaches L* > 7.

ULF waves in the Pc5 range can lead to violation of the third invariant and allow for electron radial diffusion.

Motivation – Goal


Electron PSDThe electron PSD distribution is calculated from differential fluxes as a function of fixed first (μ) and second (K) adiabatic invariants using the method described by Chen et al., 2005, 2007.

Pc5 wavesPc5 wave power is calculated from magnetic field measurements using the method described by Balasis et al., 2013.

Chorus wavesChorus wave power is calculated from the POES measurements of precipitating electron fluxes using the method described by Li et al., 2013.

Data and Methodology



Selected Events

1.March 16-18, 2013 Severe storm that caused a PSD dropout and resulted in PSD enhancement while Chorus activity was pronounced and Pc5 power limited to the storm main phase.

2. September 11-13, 2014Severe storm that caused a strong PSD dropout and resulted in the recovery of PSD at pre-storm levels for μ>300 MeV/G while Pc5 power was enhanced even after the end of the storm recovery phase.

Electron Enhancement Event (Severe Storm of March 16-18, 2013)


(Shue et al., 1998) (O'Brien and Moldwin, 2003)

15/3 16/3 17/3 18/3 19/3 20/3 21/3

15/3 16/3 17/3 18/3 19/3 20/3 21/3

15/3 16/3 17/3 18/3 19/3 20/3 21/3

15/3 16/3 17/3 18/3 19/3 20/3 21/3

SSC ICME endsRecovery Phase



Chorus Wave PowerSSC Recovery Phase



SSCRecovery Phase

Electron Depletion Event (Severe Storm of September 11-13, 2013)


10/9 11/9 12/9 13/9 14/9 15/9

SSC ICME endsRecovery Phase

10/9 11/9 12/9 13/9 14/9 15/9

10/9 11/9 12/9 13/9 14/9 15/9

10/9 11/9 12/9 13/9 14/9 15/9



Chorus Wave PowerSSC Recovery Phase



SSC Recovery Phase

Conclusions

The comparison of the two events shows that – for similar duration and power – acceleration by chorus waves excerts outward diffusion driven by Pc5 activity.

It’s the long-lasting Pc5 power enhancement that leads to PSD depletion of the electron population (or recovery to pre-storm levels in other events), indicating outward diffusion.

There is a 300 MeV/G limit in μ above which Pc5 waves can diffuse electrons.


Thank you for your attention


Combined Effects of Concurrent Pc5 and Chorus Waves on Relativistic Electron Dynamics Christos Katsavrias 1,2, Ioannis A. Daglis 2,1, Wen Li 3, Stavros.

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