scholarly journals The Magnetic Electron Ion Spectrometer: A Review of On-Orbit Sensor Performance, Data, Operations, and Science

2021 ◽  
Vol 217 (8) ◽  
Author(s):  
S. G. Claudepierre ◽  
J. B. Blake ◽  
A. J. Boyd ◽  
J. H. Clemmons ◽  
J. F. Fennell ◽  
...  
Keyword(s):  
Radiation Environment ◽  
Relativistic Electrons ◽  
Particle Radiation ◽  
Near Earth Space ◽  
Sensor Performance ◽  
Sufficient Detail ◽  
Van Allen Probes ◽  
Scientific Results ◽  
And Performance ◽  
Magnetic Electron

AbstractMeasurements from NASA’s Van Allen Probes have transformed our understanding of the dynamics of Earth’s geomagnetically-trapped, charged particle radiation. The Van Allen Probes were equipped with the Magnetic Electron Ion Spectrometers (MagEIS) that measured energetic and relativistic electrons, along with energetic ions, in the radiation belts. Accurate and routine measurement of these particles was of fundamental importance towards achieving the scientific goals of the mission. We provide a comprehensive review of the MagEIS suite’s on-orbit performance, operation, and data products, along with a summary of scientific results. The purpose of this review is to serve as a complement to the MagEIS instrument paper, which was largely completed before flight and thus focused on pre-flight design and performance characteristics. As is the case with all space-borne instrumentation, the anticipated sensor performance was found to be different once on orbit. Our intention is to provide sufficient detail on the MagEIS instruments so that future generations of researchers can understand the subtleties of the sensors, profit from these unique measurements, and continue to unlock the mysteries of the near-Earth space radiation environment.

Acceleration and Loss of Ultra-relativistic Electrons in the Earth Van Allen Radiation Belts

2021 ◽  
Author(s):  
Yuri Shprits ◽  
Hayley Allison ◽  
Alexander Drozdov ◽  
Dedong Wang ◽  
Nikita Aseev ◽  
...  
Keyword(s):  
Geomagnetic Storms ◽  
Local Heating ◽  
Rest Mass ◽  
Radiation Belts ◽  
Radiation Environment ◽  
Relativistic Electrons ◽  
Horizon 2020 ◽  
Probabilistic Forecasts ◽  
Van Allen Probes ◽  
Loss Mechanisms

<p>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.</p><p>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.</p><p>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.</p><p>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 Prediction of Adverse effects of Geomagnetic storms and Energetic Radiation (PAGER) we will study how ensemble forecasting from the Sun can produce long-term probabilistic forecasts of the radiation environment in the inner magnetosphere.</p>

scholarly journals Very-Low-Frequency transmitters bifurcate energetic electron belt in near-earth space

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Man Hua ◽  
Wen Li ◽  
Binbin Ni ◽  
Qianli Ma ◽  
Alex Green ◽  
...  
Keyword(s):  
Practical Importance ◽  
Energetic Electron ◽  
Low Frequency ◽  
Radiation Environment ◽  
Particle Radiation ◽  
Earth Space ◽  
Quantitative Evidence ◽  
Very Low Frequency ◽  
Near Earth Space ◽  
Submarine Communications

Abstract Very-Low-Frequency (VLF) transmitters operate worldwide mostly at frequencies of 10–30 kilohertz for submarine communications. While it has been of intense scientific interest and practical importance to understand whether VLF transmitters can affect the natural environment of charged energetic particles, for decades there remained little direct observational evidence that revealed the effects of these VLF transmitters in geospace. Here we report a radially bifurcated electron belt formation at energies of tens of kiloelectron volts (keV) at altitudes of ~0.8–1.5 Earth radii on timescales over 10 days. Using Fokker-Planck diffusion simulations, we provide quantitative evidence that VLF transmitter emissions that leak from the Earth-ionosphere waveguide are primarily responsible for bifurcating the energetic electron belt, which typically exhibits a single-peak radial structure in near-Earth space. Since energetic electrons pose a potential danger to satellite operations, our findings demonstrate the feasibility of mitigation of natural particle radiation environment.

Estimation of the Particle Radiation Environment at the L1 Point and in Near-Earth Space

2019 ◽  
Vol 873 (2) ◽  
pp. 112 ◽  
Author(s):  
M. Laurenza ◽  
T. Alberti ◽  
M. F. Marcucci ◽  
G. Consolini ◽  
C. Jacquey ◽  
...  
Keyword(s):  
Radiation Environment ◽  
Particle Radiation ◽  
Earth Space ◽  
Near Earth Space

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.

scholarly journals Simulation study of the energetic neutral atom (ENA) imaging monitoring of the geomagnetosphere on a lunar base

2021 ◽  
Vol 7 (3) ◽  
pp. 3-11
Author(s):  
Lu Li ◽  
Yu Qing-Long ◽  
Zhou Ping ◽  
Zhang Xin ◽  
Zhang Xian-Guo ◽  
...  
Keyword(s):  
Geomagnetic Storm ◽  
Ring Current ◽  
Sampling Interval ◽  
Base Station ◽  
Radiation Environment ◽  
Emission Model ◽  
The Moon ◽  
Imaging Data ◽  
Particle Radiation ◽  
Energy Channel

Since the moon’s revolution cycle is exactly the same as its rotation cycle, we can only see the moon always facing Earth in the same direction. Based on the clean particle radiation environment of the moon, a neutral atomic telemetry base station could be established on the lunar surface facing Earth to realize long-term continuous geomagnetic activity monitoring. Using the 20°×20° field of view, the 0.5°×0.5° angle resolution, and the ~0.17 cm²sr geometric factor, a two-dimensional ENA imager is being designed. The magnetospheric ring current simulation at a 4–20 keV energy channel for a medium geomagnetic storm (Kp=5) shows the following: 1) at ~60 Rᴇ (Rᴇ is the Earth radius), the imager can collect 10⁴ ENA events for 3 min to meet the statistical requirements for 2D coded imaging data inversion, so as to meet requirements for the analysis of the substorm ring current evolution process of magnetic storms above medium; 2) the ENA radiation loss puzzles in the magnetopause and magnetotail plasma sheet regions have been deduced and revealed using the 2-D ENA emission model. High spatial-temporal resolution ENA imaging monitoring of these two important regions will provide the measurement basis for the solar wind energy input process and generation mechanism; 3) the average sampling interval of ENA particle events is about 16 ms at the moon’s orbit; the spectral time difference for the set energy range is on the order of minutes, which can provide location information to track the trigger of geomagnetic storm particle events.

Dynamics of the Radiation Environment in the Near-Earth Space in September–November 2020 according to the Meteor-M and Electro-L Satellite Data

2021 ◽  
Vol 59 (6) ◽  
pp. 433-445
Author(s):  
I. N. Myagkova ◽  
A. V. Bogomolov ◽  
V. E. Eremeev ◽  
A. O. Shiryaev ◽  
E. A. Ginzburg
Keyword(s):  
Satellite Data ◽  
Radiation Environment ◽  
Earth Space ◽  
Near Earth Space

Simulations of the Relativistic Radiation Belt Electrons Using the VERB-3D Code

2021 ◽  
Author(s):  
Dedong Wang ◽  
Yuri Shprits ◽  
Alexander Drozdov ◽  
Nikita Aseev ◽  
Irina Zhelavskaya ◽  
...  
Keyword(s):  
Space Weather ◽  
Radiation Belt ◽  
Model Performance ◽  
Dynamic Evolution ◽  
Relativistic Electrons ◽  
Outer Radiation Belt ◽  
Chorus Waves ◽  
Van Allen Probes ◽  
Radiation Belt Electrons ◽  
Simulation Results

&lt;p&gt;Using the three-dimensional Versatile Electron Radiation Belt (VERB-3D) code, we perform simulations to investigate the dynamic evolution of relativistic electrons in the Earth&amp;#8217;s outer radiation belt. In our simulations, we use data from the Geostationary Operational Environmental Satellites (GOES) to set up the outer boundary condition, which is the only data input for simulations. The magnetopause shadowing effect is included by using last closed drift shell (LCDS), and it is shown to significantly contribute to the dropouts of relativistic electrons at high $L^*$. We validate our simulation results against measurements from Van Allen Probes. In long-term simulations, we test how the latitudinal dependence of chorus waves can affect the dynamics of the radiation belt electrons. Results show that the variability of chorus waves at high latitudes is critical for modeling of megaelectron volt (MeV) electrons. We show that, depending on the latitudinal distribution of chorus waves under different geomagnetic conditions, they cannot only produce a net acceleration but also a net loss of MeV electrons. Decrease in high&amp;#8208;latitude chorus waves can tip the balance between acceleration and loss toward acceleration, or alternatively, the increase in high&amp;#8208;latitude waves can result in a net loss of MeV electrons. Variations in high&amp;#8208;latitude chorus may account for some of the variability of MeV electrons.&amp;#160;&lt;/p&gt;&lt;p&gt;Our simulation results for the NSF GEM Challenge Events show that the position of the plasmapause plays a significant role in the dynamic evolution of relativistic electrons. We also perform simulations for the COSPAR International Space Weather Action Team (ISWAT) Challenge for the year 2017. The COSPAR ISWAT is a global hub for collaborations addressing challenges across the field of space weather. One of the objectives of the G3-04 team &amp;#8220;Internal Charging Effects and the Relevant Space Environment&amp;#8221; is model performance assessment and improvement. One of the expected outputs is a more systematic assessment of model performance under different conditions. The G3-04 team proposed performing benchmarking challenge runs. We &amp;#8216;fly&amp;#8217; a virtual satellite through our simulation results and compare the simulated differential electron fluxes at 0.9 MeV and 57.27 degrees local pitch-angle with the fluxes measured by the Van Allen Probes. In general, our simulation results show good agreement with observations. We calculated several different matrices to validate our simulation results against satellite observations.&lt;/p&gt;

Dynamics of the Earth’s Particle Radiation Environment

2009 ◽  
Vol 147 (3-4) ◽  
pp. 187-231 ◽  
Author(s):  
Rami Vainio ◽  
Laurent Desorgher ◽  
Daniel Heynderickx ◽  
Marisa Storini ◽  
Erwin Flückiger ◽  
...  
Keyword(s):  
Radiation Environment ◽  
Particle Radiation

scholarly journals Monitoring, analysis and post-casting of the Earth’s particle radiation environment during February 14–March 5, 2014

2019 ◽  
Vol 9 ◽  
pp. A29
Author(s):  
Vladimir Kalegaev ◽  
Mikhail Panasyuk ◽  
Irina Myagkova ◽  
Yulia Shugay ◽  
Natalia Vlasova ◽  
...  
Keyword(s):  
Space Weather ◽  
Geomagnetic Storms ◽  
Monitoring Data ◽  
Radiation Environment ◽  
Satellite Measurement ◽  
Outer Radiation Belt ◽  
Earth Space ◽  
Near Earth Space ◽  
Advantages And Disadvantages ◽  
Operational Models

Internet-based system of Space Monitoring Data Center (SMDC) of Skobeltsyn Institute of Nuclear Physics of Moscow State University (SINP MSU) has been developed to predict and analyze radiation conditions in near-Earth space. This system contains satellite measurement databases and operational models and devoted to collect, store and process space weather monitoring data in the near real-time. SMDC operational services acquire data from ACE, SDO, GOES, Electro-L, Meteor-M satellites and use them for forecasting, now-casting and post-casting of space weather factors. This paper is intended to give overview of operational services of SMDC Internet-based system and demonstrate their possibilities and limitations to analyze space weather phenomena and predict radiation and geomagnetic conditions in the near-Earth space during February 14–March 5, 2014. This prolonged period of high level solar and geomagnetic activity demonstrates various manifestations of the space weather: solar proton events, geomagnetic storms and outer radiation belt (RB) dynamics. Solar sources of interplanetary space disturbances and their influence on geomagnetic and radiation state of the Earth’s magnetosphere were described using output coming from SMDC’ Web-based applications. Validation of SMDC’s operational models was performed based on the quality of description of the physical conditions in near-Earth space during space weather events observed from February 14 to March 5, 2014. The advantages and disadvantages of SMDC operational services are illustrated and discussed based on comparison with data obtained from satellites.

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