Dr
David G. Sibeck
02/07/2013, 09:00
Waves, Wave-Particle Interactions and Radiation Belt Dynamics
Oral
The comprehensive particle and field coverage provided by the identical Van Allen Probe spacecraft will enable a revolution in our understanding of the processes that produce the Earth's radiation belts. This discussion addresses initial results from each of the investigations on the mission, demonstrating the wide variety of research now underway.
Dr
PAUL OBRIEN
(The Aerospace Corporation)
02/07/2013, 09:20
Waves, Wave-Particle Interactions and Radiation Belt Dynamics
Oral
The electron content of inner radiation zone and slot region are two seldom studied regions of the magnetosphere because of lack of good access and the serious background conditions there. The backgrounds created by the high energy protons that exist in the inner radiation zone and extend into the slot region make it difficult to obtain good measurements of the electron distributions there....
Dr
Drew Turner
(University of California, Los Angeles)
02/07/2013, 10:00
Waves, Wave-Particle Interactions and Radiation Belt Dynamics
Oral
In Earth's outer radiation belt, flux "dropout" events involve the sudden decrease of electron fluxes by up to several orders of magnitude in only a few hours, and the dominant mechanism responsible for dropouts is still debated. On 30 September 2012, a major dropout occurred throughout the entire outer radiation belt during the main phase of a strong geomagnetic storm. Here, we investigate...
Prof.
Ioannis Daglis
(National Observatory of Athens)
02/07/2013, 10:20
Waves, Wave-Particle Interactions and Radiation Belt Dynamics
Oral
The Monitoring, Analyzing and Assessing Radiation Belt Loss and Energization (MAARBLE) project has two focussed and synergistic aims: to advance scientific research on radiation belt dynamics; and to enhance data exploitation of European space missions through the combined use of European and US spacecraft measurements and ground-based observations.
MAARBLE employs multi-spacecraft...
Ian Robert Mann
(Dept Physics, Univ Alberta, Edmonton, AB, Canada)
02/07/2013, 10:40
Waves, Wave-Particle Interactions and Radiation Belt Dynamics
Oral
Ultra-low frequency (ULF) waves in the Pc4-5 band can be excited in the magnetosphere by the solar wind. Much recent work has shown how ULF wave power is strongly correlated with solar wind speed. However, little attention has been paid the dynamics of ULF wave power penetration onto low L-shells in the inner magnetosphere. We use more than a solar cycle of ULF wave data, derived from...
Dr
Vladimir Krasnoselskikh
(LPC2E)
02/07/2013, 11:30
Waves, Wave-Particle Interactions and Radiation Belt Dynamics
Oral
For the modelling of the dynamics and evolution of the radiation belts, it is necessary to possess precise estimates of the lifetime of energetic particles and of the characteristic time of particle acceleration for different energies and pitch-angles in a wide range of L-shells. The lifetimes of electrons trapped in Earth’s radiation belts are supposed to be determined by a process of...
Dr
Louis Ozeke
(University of Alberta)
02/07/2013, 12:10
Waves, Wave-Particle Interactions and Radiation Belt Dynamics
Oral
We present analytic expressions for ULF wave derived radiation belt radial diffusion coefficients, as a function of L and Kp, which can easily be incorporated into global radiation belt transport models. The diffusion coefficients are derived from statistical representations of ULF wave electric field power, mapped from ground-magnetometer data, and from in-situ characterisations of...
Dr
Georgios Balasis
(National Observatory of Athens)
02/07/2013, 12:30
Waves, Wave-Particle Interactions and Radiation Belt Dynamics
Oral
We have found a specific time interval during the Halloween 2003 magnetic storm, when the Cluster and CHAMP spacecraft were in good local time (LT) conjunction, and have examined the Pc3 (22-100 mHz) and Pc4-5 (1-22 mHz) ULF wave activity using data from Cluster, CHAMP and the CARISMA magnetometer network. We provide evidence for the first simultaneous observation of a Pc3 ULF wave event in...
Prof.
Ian Mann
(University of Alberta)
02/07/2013, 12:50
Waves, Wave-Particle Interactions and Radiation Belt Dynamics
Oral
We will present an example of unusual long-lasting EMIC wave event from October 11, 2012 which occurred in the recovery of a moderate geomagnetic storm (with minimum Dst=-111 nT on October 9, 2012). The wave activity spanned the interval of almost 24 hours MLT and was detected at multiple CARISMA magnetometer stations. During the event, the Van Allen Probe B had a beautiful conjunction with...
Dr
Benjamin Grison
(Institute of Atmospheric Physics ASCR)
02/07/2013, 13:10
Waves, Wave-Particle Interactions and Radiation Belt Dynamics
Oral
EMIC triggered emissions have been reported in the inner magnetosphere at the edge of the nightside plasmapause [Pickett et al., 2010]. The generation mechanism proposed by Omura et al. [2010] is very similar to the one of the whistler chorus emissions. Corresponding simulation results agree with observations and theory [Shoji et Omura, 2011]. The main characteristics of these emissions...
Prof.
Dennis Papadopoulos
(University of Maryland)
03/07/2013, 09:00
Waves, Wave-Particle Interactions and Radiation Belt Dynamics
Invited
After many decades of successful and frontier RB science fundamental physics questions remain either unresolved or the answers involve great uncertainty. Current experimental techniques that use mainly correlative spacecraft observations have difficulties in resolving questions such as:
What is the attenuation rate of Shear Alfven (SA) waves propagating towards the conjugates? Are there...
Prof.
Richard Horne
(British Antarctic Survey)
03/07/2013, 09:40
Waves, Wave-Particle Interactions and Radiation Belt Dynamics
Oral
Global models of the Van Allen radiation belts usually include resonant wave-particle interactions as a diffusion process, but there is a large uncertainty over the diffusion rates. Here we present a new diffusion matrix for whistler mode chorus waves that can be used in such models. Data from seven satellites are used to construct 3,536 power spectra for upper and lower band chorus for 1.5...
Dr
Nigel Meredith
(British Antarctic Survey)
03/07/2013, 10:00
Waves, Wave-Particle Interactions and Radiation Belt Dynamics
Oral
The origin of plasmaspheric hiss, the electromagnetic emission responsible for the gap between the inner and outer radiation belts, has been debated for over four decades. Recently a new theory proposed that chorus, which is excited in the equatorial region outside the plasmapause, can propagate to low altitudes on the dayside and evolve into plasmaspheric hiss. Here we combine data from six...
Ondrej Santolik
(IAP Prague & Charles University in Prague)
03/07/2013, 10:20
Waves, Wave-Particle Interactions and Radiation Belt Dynamics
Oral
Whistler-mode waves in the Earth's inner magnetosphere significantly contribute to wave-particle interactions at different scales. Especially, whistler-mode chorus has been shown to play an important role in the dynamics of the outer Van Allen radiation belt. These waves are generated by nonlinear wave-particle interactions occurring in the region close to the geomagnetic equator. They are...
Dr
Oleksiy Agapitov
(LPC2E/CNRS)
03/07/2013, 10:40
Waves, Wave-Particle Interactions and Radiation Belt Dynamics
Oral
ELF/VLF waves play a crucial role in the dynamics of the radiation belts, and are partly responsible for the main losses and the acceleration of energetic electrons. Modeling wave-particle interactions requires detailed information of wave amplitudes and wave-normal distribution over L-shells and over magnetic latitudes for different geomagnetic activity conditions. We performed a statistical...
O. Santolik
03/07/2013, 11:30
Waves, Wave-Particle Interactions and Radiation Belt Dynamics
Oral
The physics of the creation, loss, and transport of radiation belt particles is intimately connected to the electric and magnetic fields which mediate these processes. A large range of field and particle interactions are involved in this physics from large-scale ring current ion and magnetic field dynamics to microscopic kinetic interactions of whistler-mode chorus waves with energetic...
Dr
Harri Laakso
(ESA)
03/07/2013, 12:10
Waves, Wave-Particle Interactions and Radiation Belt Dynamics
Oral
The inner magnetosphere contains two plasma regimes, the plasmasphere and radiation belts, that are coupled to each other. The plasmasphere can support various wave modes that can cause either energization of radiation belt particles or their loss. In particular hiss emission is believed to provide a major loss mechanism of energetic particles Using in-situ multi-point observations from the...
Dr
Iannis Dandouras
(IRAP, CNRS / University of Toulouse)
03/07/2013, 14:30
Waves, Wave-Particle Interactions and Radiation Belt Dynamics
Oral
The Earth’s plasmasphere dominates the mass content of the inner magnetosphere and therefore plays an essential role in governing the radiation belt dynamics. The configuration of the plasmasphere is highly sensitive to geomagnetic disturbances. During extended periods of relatively quiet geomagnetic conditions the outer plasmasphere can become diffuse, with a gradual fall-off of plasma...
Mrs
Angélica SICARD-PIET
(ONERA)
03/07/2013, 15:10
Waves, Wave-Particle Interactions and Radiation Belt Dynamics
Oral
Wave particle interactions, which play a major role in electron radiation belts dynamics, are controlled by two main parameters: the characteristics of the wave (such as the wave type, its power spectrum and wave normal angle) and the characteristics of the ambient plasma. The purpose of this study is to assess how variations in the plasma density affect diffusion rates for chorus,...
Prof.
Richard Horne
(British Antarctic Survey)
03/07/2013, 15:30
Waves, Wave-Particle Interactions and Radiation Belt Dynamics
Oral
Satellites can be damaged by high energy charged particles in the Earth’s radiation belts and during solar energetic particle (SEP) events. Here we review the growing reliance on satellite services, new vulnerabilities to space weather, and previous events that have led to loss of service. We describe a new European system to forecast the radiation belts up to 3 h ahead, which has three unique...
