The Response of Earth's Electron Radiation Belts to Geomagnetic Storms: Statistics From the Van Allen Probes Era Including Effects From Different Storm Drivers

Measurements from the Van Allen Probes mission clearly demonstrated that the radiation belts cannot be considered as a bulk population above approximately electron rest mass. Ultra-relativistic electrons (~>4Mev) form a new population that shows a very different morphology (e.g. very narrow remnant belts) and slow but sporadic acceleration.We show that acceleration to multi-MeV energies can not only result of a two-step processes consisting of local heating and radial diffusion but occurs locally due to energy diffusion by whistler mode waves. Local heating appears to be able to transport electrons in energy space from 100s of keV all the way to ultra-relativistic energies (>7MeV). Acceleration to such high energies occurs only for the conditions when cold plasma in the trough region is extremely depleted down to the values typical for the plasma sheet.There is also a clear difference between the loss mechanisms at MeV and multi MeV energies The difference between the loss mechanisms at MeV and multi-MeV energies is due to EMIC waves that can very efficiently scatter ultra-relativistic electrons, but leave MeV electrons unaffected.We also present how the new understanding gained from the Van Allen Probes mission can be used to produce the most accurate data assimilative forecast. Under the recently funded EU Horizon 2020 Project&#160;Prediction of Adverse effects of Geomagnetic storms and Energetic Radiation&#160;(PAGER) we will study how ensemble forecasting from the Sun can produce long-term probabilistic forecasts of the radiation environment in the inner magnetosphere.

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Refilling of the slot region between the inner and outer electron radiation belts during geomagnetic storms

Journal of Geophysical Research Atmospheres ◽

10.1029/2006ja012176 ◽

2007 ◽

Vol 112 (A6) ◽

pp. n/a-n/a ◽

Cited By ~ 71

Author(s):

R. M. Thorne ◽

Y. Y. Shprits ◽

N. P. Meredith ◽

R. B. Horne ◽

W. Li ◽

...

Keyword(s):

Geomagnetic Storms ◽

Radiation Belts ◽

Electron Radiation ◽

Outer Electron

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Increase in seismic activity near the footprints of new radiation belts forming after geomagnetic storms

10.5194/egusphere-egu21-2149 ◽

2021 ◽

Author(s):

Nursultan Toyshiev ◽

Galina Khachikyan ◽

Beibit Zhumabayev

Keyword(s):

Geomagnetic Storm ◽

Seismic Activity ◽

Radiation Belt ◽

Geomagnetic Storms ◽

Radiation Belts ◽

Tien Shan ◽

Relativistic Electrons ◽

Inner Magnetosphere ◽

Van Allen Probes ◽

Northern Tien Shan

Recently, attention was drawn [1] that after geomagnetic storms that cause formation of new radiation belts in slot region or in the inner magnetosphere, after about 2 months, there is an increase in seismic activity near the footprints of geomagnetic lines of new radiation belts. More detailed studies showed [2] that on May 30, 1991, an earthquake M=7.0 occurred in Alaska with (54.57N, 161.61E) near the footprint of geomagnetic line L = 2.69 belonging to new radiation belt, which was observed by the CRRES satellite [3] around geomagnetic lines 2<L<3 after geomagnetic storm on March 24, 1991. After geomagnetic storm on September 3, 2012, the Van Allen Probes satellites observed new radiation belt around 3.0&#8804;L&#8804;3.5 [4], and about 2 months later, on October 28, 2012, earthquake M=7.8 occurred off the coast of Canada (52.79N, 132.1W) near the footprint of geomagnetic line L=3.32 belonging to the new radiation belt. Also, Van Allen Probes observed new radiation belt around L=1.5-1.8 after geomagnetic storm on June 23, 2015 [5], and ~2 months later, in September 2015, seismic activity noticeably increased near the footprint of these geomagnetic lines. We consider variations in seismic activity in connection with the strongest geomagnetic storms in 2003 with Dst~- 400 nT (Halloween Storm) and the formation of a belt of relativistic electrons in the inner magnetosphere around L~1.5 existed until the end of 2005 as observed SAMPEX [6]. Analysis of data from the USGS global seismological catalog showed that near the footprint of geomagnetic lines L=1.4-1.6 the number of earthquakes with M&#8805;4.5 increased in 2003-2004 by ~70% compared with their number in two previous years. On the Northern Tien Shan, on December 1, 2003 a strong for the region earthquake M=6.0 occurred on the border of Kazakhstan and China (42.9N, 80.5E) near the footprint of L = 1.63, adjacent to the new radiation belt.

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Nonstorm time dynamics of electron radiation belts observed by the Van Allen Probes

Geophysical Research Letters ◽

10.1002/2013gl058912 ◽

2014 ◽

Vol 41 (2) ◽

pp. 229-235 ◽

Cited By ~ 42

Author(s):

Zhenpeng Su ◽

Fuliang Xiao ◽

Huinan Zheng ◽

Zhaoguo He ◽

Hui Zhu ◽

...

Keyword(s):

Radiation Belts ◽

Electron Radiation ◽

Time Dynamics ◽

Van Allen Probes

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On the effect of ULF waves on the outer radiation belt during geomagnetic storms

10.5194/egusphere-egu21-5977 ◽

2021 ◽

Author(s):

Christopher Lara ◽

Pablo S. Moya ◽

Victor Pinto ◽

Javier Silva ◽

Beatriz Zenteno

Keyword(s):

Relativistic Electron ◽

Radiation Belt ◽

Geomagnetic Storms ◽

Cumulative Effect ◽

Radiation Belts ◽

Ulf Waves ◽

Relativistic Electrons ◽

Relative Role ◽

Outer Radiation Belt ◽

Ulf Wave

The inner magnetosphere is a very important region to study, as with satellite-based communications increasing day after day, possible disruptions are especially relevant due to the possible consequences in our daily life. It is becoming very important to know how the radiation belts behave, especially during strong geomagnetic activity. The radiation belts response to geomagnetic storms and solar wind conditions is still not fully understood, as relativistic electron fluxes in the outer radiation belt can be depleted, enhanced or not affected following intense activity. Different studies show how these results vary in the face of different events. As one of the main mechanisms affecting the dynamics of the radiation belt are wave-particle interactions between relativistic electrons and ULF waves. In this work we perform a statistical study of the relationship between ULF wave power and relativistic electron fluxes in the outer radiation belt during several geomagnetic storms, by using magnetic field and particle fluxes data measured by the Van Allen Probes between 2012 and 2017. We evaluate the correlation between the changes in flux and the cumulative effect of ULF wave activity during the main and recovery phases of the storms for different position in the outer radiation belt and energy channels. Our results show that there is a good correlation between the presence of ULF waves and the changes in flux during the recovery phase of the storm and that correlations vary as a function of energy. Also, we can see in detail how the ULF power change for the electron flux at different L-shell We expect these results to be relevant for the understanding of the relative role of ULF waves in the enhancements and depletions of energetic electrons in the radiation belts for condition described.

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