Electron filling and proton loss in radiation belts and SAA during 2018 storm based on ZH-1 satellite observations

2021 ◽  
Author(s):  
Zhenxia Zhang
Keyword(s):  
Geomagnetic Storm ◽  
Radiation Belt ◽  
Electron Flux ◽  
Outer Boundary ◽  
Energetic Electron ◽  
High Energy ◽  
Radiation Belts ◽  
High Energy Particle ◽  
Van Allen Probes ◽  
Proton Loss

<p>Based on data from the ZH-1 satellites, companied with Van Allen Probes and NOAA observations, we analyze the high energy particle evolutions in radiation belts, slot region and SAA during August 2018 major geomagnetic storm (minimum Dst ≈ −190 nT). </p><p>  1) Relativistic electron enhancements in extremely low L-shell regions (reaching L ∼ 3) were observed during storm. Contrary to what occurs in the outer belt, such an intense and deep electron penetration event is rare and more interesting. Strong whistler-mode (chorus and hiss) waves, with amplitudes 81–126 pT, were also observed in the extremely low L-shell simultaneously (reaching L ∼ 2.5) where the plasmapause was suppressed. The bounce-averaged diffusion coefficient calculations support that the chorus waves can play a significantly important role in diffusing and accelerating the 1–3 MeV electrons even in such low L-shells during storms.</p><p>2) A robust evidence is clearly demonstrated that the energetic electron flux with energy 30∼600 keV are increased by 2∼3 times in the inner radiation belt near equator and SAA region on dayside during the major geomagnetic storm. This is the first time that the 100s keV electron flux enhancement is reported to be potentially induced by the interaction with magnetosonic waves in extremely low L-shells (L<2) observed by Van Allen Probes. Proton loss in outer boundary of inner radiation belt takes place in energy of 2~220 MeV extensively during the occurrence of this storm but the loss mechanism is energy dependence which is consistent with some previous studies. It is confirmed that the magnetic field line curvature scattering plays a significant role in the proton loss phenomenon in energy 30-100 MeV during this storm. This work provides a beneficial help to comprehensively understand the charged particles trapping and loss in SAA region and inner radiation belt dynamic physics.</p>

Modelling the Rebuilding the Radiation Belt Following a Drop-out Event from Acceleration of the Seed Population

2020 ◽  
Author(s):  
Hayley Allison ◽  
Yuri Shprits ◽  
Sarah Glauert ◽  
Richard Horne ◽  
Dedong Wang
Keyword(s):  
Boundary Condition ◽  
Radiation Belt ◽  
Electron Flux ◽  
Outer Boundary ◽  
Dynamic Environment ◽  
Drop Out ◽  
Sequence Of Events ◽  
Seed Population ◽  
Van Allen Probes ◽  
Open Question

<p><span>The Earth’s electron radiation belts are a dynamic environment and can change dramatically on short timescales. From Van Allen Probes observations, we see storm time drop-out events followed by a rapid recovery of the electron flux over a broad range of energies. Substorms can supply a seed population of new electrons to the radiation belt region, which are then energised by a number of processes, rebuilding the belts. </span>However, how the electron flux is replenished across energy space, and the sequence of events leading to flux enhancements, remains an open question. Here we use a 3-D radiation belt model to explore how the seed population is accelerated to 1 MeV on realistic timescales, comparing the output to Van Allen Probes observations. By using a low energy boundary condition derived by POES data we encompass the whole radiation belt region, employing an open outer boundary condition. This approach isolates the contribution of seed population changes and allows electron flux variations over a broad range of L* to be studied. Using the model, we explore the contribution of both local acceleration and radial diffusion and demonstrate that the timing and duration of these two processes, particularly in relation to one another, is important to determine how the radiation belt rebuilds.</p>

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

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

<p>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≤L≤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≥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.</p>

scholarly journals Multi-satellite simultaneous observations of magnetopause and atmospheric losses of radiation belt electrons during an intense solar wind dynamic pressure pulse

2016 ◽  
Vol 34 (5) ◽  
pp. 493-509 ◽  
Author(s):  
Zheng Xiang ◽  
Binbin Ni ◽  
Chen Zhou ◽  
Zhengyang Zou ◽  
Xudong Gu ◽  
...  
Keyword(s):  
Solar Wind ◽  
Radiation Belt ◽  
Pressure Pulse ◽  
Electron Flux ◽  
Dynamic Pressure ◽  
Energetic Electron ◽  
Solar Wind Dynamic Pressure ◽  
Angle Scattering ◽  
Radiation Belt Electrons ◽  
Atmospheric Loss

<p><strong>Abstract.</strong> Radiation belt electron flux dropouts are a kind of drastic variation in the Earth's magnetosphere, understanding of which is of both scientific and societal importance. Using electron flux data from a group of 14 satellites, we report multi-satellite simultaneous observations of magnetopause and atmospheric losses of radiation belt electrons during an event of intense solar wind dynamic pressure pulse. When the pulse occurred, magnetopause and atmospheric loss could take effect concurrently contributing to the electron flux dropout. Losses through the magnetopause were observed to be efficient and significant at <i>L</i> ≳ 5, owing to the magnetopause intrusion into <i>L</i> ∼ 6 and outward radial diffusion associated with sharp negative gradient in electron phase space density. Losses to the atmosphere were directly identified from the precipitating electron flux observations, for which pitch angle scattering by plasma waves could be mainly responsible. While the convection and substorm injections strongly enhanced the energetic electron fluxes up to hundreds of keV, they could delay other than avoid the occurrence of electron flux dropout at these energies. It is demonstrated that the pulse-time radiation belt electron flux dropout depends strongly on the specific interplanetary and magnetospheric conditions and that losses through the magnetopause and to the atmosphere and enhancements of substorm injection play an essential role in combination, which should be incorporated as a whole into future simulations for comprehending the nature of radiation belt electron flux dropouts.</p>

scholarly journals The effects of the big storm events in the first half of 2015 on the radiation belts observed by EPT/PROBA-V

2016 ◽  
Vol 34 (1) ◽  
pp. 75-84 ◽  
Author(s):  
V. Pierrard ◽  
G. Lopez Rosson
Keyword(s):  
Charged Particle ◽  
High Resolution ◽  
Geomagnetic Storm ◽  
Energetic Particle ◽  
High Energy ◽  
Radiation Belts ◽  
Radiation Environment ◽  
Storm Event ◽  
Storm Events ◽  
Particle Radiation

Abstract. With the energetic particle telescope (EPT) performing with direct electron and proton discrimination on board the ESA satellite PROBA-V, we analyze the high-resolution measurements of the charged particle radiation environment at an altitude of 820 km for the year 2015. On 17 March 2015, a big geomagnetic storm event injected unusual fluxes up to low radial distances in the radiation belts. EPT electron measurements show a deep dropout at L > 4 starting during the main phase of the storm, associated to the penetration of high energy fluxes at L < 2 completely filling the slot region. After 10 days, the formation of a new slot around L = 2.8 for electrons of 500–600 keV separates the outer belt from the belt extending at other longitudes than the South Atlantic Anomaly. Two other major events appeared in January and June 2015, again with injections of electrons in the inner belt, contrary to what was observed in 2013 and 2014. These observations open many perspectives to better understand the source and loss mechanisms, and particularly concerning the formation of three belts.

Variation of Radiation Belt Electron Flux During CME‐ and CIR‐Driven Geomagnetic Storms: Van Allen Probes Observations

2019 ◽  
Vol 124 (8) ◽  
pp. 6524-6540 ◽  
Author(s):  
Megha Pandya ◽  
Veenadhari Bhaskara ◽  
Yusuke Ebihara ◽  
Shrikanth G. Kanekal ◽  
Daniel N. Baker
Keyword(s):  
Radiation Belt ◽  
Electron Flux ◽  
Geomagnetic Storms ◽  
Van Allen Probes

scholarly journals A radiation belt of energetic protons located between Saturn and its rings

Science ◽  
2018 ◽  
Vol 362 (6410) ◽  
pp. eaat1962 ◽  
Author(s):  
E. Roussos ◽  
P. Kollmann ◽  
N. Krupp ◽  
A. Kotova ◽  
L. Regoli ◽  
...  
Keyword(s):  
Radiation Belt ◽  
Cosmic Ray ◽  
High Energy ◽  
Radiation Belts ◽  
Exchange Reactions ◽  
Dipole Magnetic Field ◽  
Imaging Instrument ◽  
Multiple Charge ◽  
Strong Dipole ◽  
Dense Atmosphere

Saturn has a sufficiently strong dipole magnetic field to trap high-energy charged particles and form radiation belts, which have been observed outside its rings. Whether stable radiation belts exist near the planet and inward of the rings was previously unknown. The Cassini spacecraft’s Magnetosphere Imaging Instrument obtained measurements of a radiation belt that lies just above Saturn’s dense atmosphere and is decoupled from the rest of the magnetosphere by the planet’s A- to C-rings. The belt extends across the D-ring and comprises protons produced through cosmic ray albedo neutron decay and multiple charge-exchange reactions. These protons are lost to atmospheric neutrals and D-ring dust. Strong proton depletions that map onto features on the D-ring indicate a highly structured and diverse dust environment near Saturn.

Determining latitudinal extent of energetic electron precipitation using MEPED on-board NOAA POES

2020 ◽  
Author(s):  
Eldho Midhun Babu ◽  
Hilde Nesse Tyssøy ◽  
Christine Smith-Johnsen ◽  
Ville Aleksi Maliniemi ◽  
Josephine Alessandra Salice ◽  
...  
Keyword(s):  
Solar Wind ◽  
Radiation Belt ◽  
Climate Models ◽  
Stratospheric Ozone ◽  
Energetic Electron ◽  
Radiation Belts ◽  
Atmospheric Dynamics ◽  
Electron Precipitation ◽  
Atmospheric Effects ◽  
The Earth

&lt;p&gt;Energetic electron precipitation (EEP) from the plasma sheet and the radiation belts, can collide with gases in the atmosphere and deposit their energy. EEP increase the production of NOx and HOx, which will catalytically destroy stratospheric ozone, an important element of atmospheric dynamics. The particle precipitation also causes variation in the radiation belt population. Therefore, measurement of latitudinal extend of the precipitation boundaries is important in quantifying atmospheric effects of Sun-Earth interaction and threats to spacecrafts and astronauts in the Earth&amp;#8217;s radiation belt. &lt;br&gt;This study uses measurements by MEPED detectors of six NOAA/POES and EUMETSAT/METOP satellites during the year 2010 to determine the latitudinal boundaries of EEP and its variability with geomagnetic activity and solar wind drivers. Variation of the boundaries with respect to different particle energies and magnetic local time is studied. The result will be a key element for constructing a model of EEP variability to be applied in atmosphere climate models.&lt;/p&gt;

Substorm Injections as a Source of Relativistic Electrons in Earth’s Outer Radiation Belt

2020 ◽  
Author(s):  
Drew Turner ◽  
Ian Cohen ◽  
Kareem Sorathia ◽  
Sasha Ukhorskiy ◽  
Geoff Reeves ◽  
...  
Keyword(s):  
Phase Space ◽  
Plasma Sheet ◽  
Radiation Belt ◽  
Energetic Electron ◽  
Local Source ◽  
Relativistic Electrons ◽  
Phase Space Density ◽  
Outer Radiation Belt ◽  
Space Density ◽  
Van Allen Probes

&lt;p&gt;Earth&amp;#8217;s magnetotail plasma sheet plays a crucial role in the variability of Earth&amp;#8217;s outer electron radiation belt. Typically, injections of energetic electrons from Earth&amp;#8217;s magnetotail into the outer radiation belt and inner magnetosphere during periods of substorm activity are not observed exceeding ~300 keV. &amp;#160;Consistent with that, phase space density radial distributions of electrons typically indicate that for electrons below ~300 keV, there is a source of electrons in the plasma sheet while for electrons with energies above that, there is a local source within the outer radiation belt itself.&amp;#160; However, here we ask the question: is this always the case or can the plasma sheet provide a direct source of relativistic (&gt; ~500 keV) electrons into Earth&amp;#8217;s outer radiation belt via substorm injection? Using phase space density analysis for fixed values of electron first and second adiabatic invariants, we use energetic electron data from NASA&amp;#8217;s Van Allen Probes and Magnetospheric Multiscale (MMS) missions during periods in which MMS observed energetic electron injections in the plasma sheet while Van Allen Probes concurrently observed injections into the outer radiation belt. We report on cases that indicate there was a sufficient source of up to &gt;1 MeV electrons in the electron injections in the plasma sheet as observed by MMS, yet Van Allen Probes did not see those energies injected inside of geosynchronous orbit.&amp;#160; From global insight with recent test-particle simulations in global, dynamic magnetospheric fields, we offer an explanation for why the highest-energy electrons might not be able to inject into the outer belt even while the lower energy (&lt; ~300 keV) electrons do. Two other intriguing points that we will discuss concerning these results are: i) what acceleration mechanism is capable of producing such abundance of relativistic electrons at such large radial distances (X-GSE &lt; -10 RE) in Earth&amp;#8217;s magnetotail? and ii) during what conditions (if any) might injections of relativistic electrons be able to penetrate into the outer belt?&lt;/p&gt;

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