scholarly journals From solar sneezing to killer electrons: outer radiation belt response to solar eruptions

2019 ◽  
Vol 377 (2148) ◽  
pp. 20180097 ◽  
Author(s):  
Ioannis A. Daglis ◽  
Christos Katsavrias ◽  
Marina Georgiou
Keyword(s):  
Electric Fields ◽  
Space Weather ◽  
High Speed ◽  
Radiation Belt ◽  
Interplanetary Space ◽  
Plasma Waves ◽  
Potential Hazard ◽  
Interplanetary Coronal Mass Ejections ◽  
Outer Radiation Belt ◽  
Solar Eruptions

Electrons in the outer Van Allen (radiation) belt occasionally reach relativistic energies, turning them into a potential hazard for spacecraft operating in geospace. Such electrons have secured the reputation of satellite killers and play a prominent role in space weather. The flux of these electrons can vary over time scales of years (related to the solar cycle) to minutes (related to sudden storm commencements). Electric fields and plasma waves are the main factors regulating the electron transport, acceleration and loss. Both the fields and the plasma waves are driven directly or indirectly by disturbances originating in the Sun, propagating through interplanetary space and impacting the Earth. This paper reviews our current understanding of the response of outer Van Allen belt electrons to solar eruptions and their interplanetary extensions, i.e. interplanetary coronal mass ejections and high-speed solar wind streams and the associated stream interaction regions.This article is part of the theme issue ‘Solar eruptions and their space weather impact’.

scholarly journals Space Weather, SuperDARN and the Tasmanian Tiger

1997 ◽  
Vol 50 (4) ◽  
pp. 773 ◽  
Author(s):  
Raymond A. Greenwald
Keyword(s):  
Solar Wind ◽  
Electric Fields ◽  
Space Weather ◽  
Interplanetary Space ◽  
Rapid Evolution ◽  
Upper Atmosphere ◽  
Global Network ◽  
Pressure Gradients ◽  
Earth’S Magnetosphere ◽  
Earth's Magnetosphere

The plasma environment extending from the solar surface through interplanetary space to the outermost reaches of the Earth’s atmosphere and magnetic field is dynamic, often disturbed, and capable of harming humans and damaging manmade systems. Disturbances in this environment have been identified as space weather disturbances. At the present time there is growing interest in monitoring and predicting space weather disturbances. In this paper we present some of the difficulties involved in achieving this goal by comparing the processes that drive tropospheric-weather systems with those that drive space-weather systems in the upper atmosphere and ionosphere. The former are driven by pressure gradients which result from processes that heat and cool the atmosphere. The latter are driven by electric fields that result from interactions between the streams of ionised gases emerging from the Sun (solar wind) and the Earth’s magnetosphere. Although the dimensions of the Earth’s magnetosphere are vastly greater than those of tropospheric weather systems, the global space-weather response to changes in the solar wind is much more rapid than the response of tropospheric-weather systems to changing conditions. We shall demonstrate the rapid evolution of space-weather systems in the upper atmosphere through measurements with a global network of radars known as SuperDARN. We shall also describe how the SuperDARN network is evolving, including a newly funded Australian component known as the Tasman International Geospace Environmental Radar (TIGER).

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

<p>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’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‐latitude chorus waves can tip the balance between acceleration and loss toward acceleration, or alternatively, the increase in high‐latitude waves can result in a net loss of MeV electrons. Variations in high‐latitude chorus may account for some of the variability of MeV electrons. </p><p>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 “Internal Charging Effects and the Relevant Space Environment” 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 ‘fly’ 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.</p>

Statistical Analysis of Extreme Electron Fluxes in the Radiation Belts

2017 ◽  
Vol 13 (S335) ◽  
pp. 128-131
Author(s):  
Vanina Lanabere ◽  
Sergio Dasso
Keyword(s):  
Distribution Function ◽  
Space Weather ◽  
Radiation Belt ◽  
Weather Conditions ◽  
Value Theory ◽  
Cumulative Distribution ◽  
Outer Radiation Belt ◽  
Weather Events ◽  
Polar Satellite ◽  
Energy Channels

AbstractThe main aim of this work is to study the frequency of extreme Space Weather events, in particular to analyse the tails of the daily averaged electron fluxes distribution function for different channels of energy between 0.249–1.192 MeV measured at ~ 600 km of altitude with the particle detector ICARE-NG/CARMEN-1 on board argentinian polar satellite SAC-D. An extreme value theory was applied to estimate the maximum values of the electron flux in the outer radiation belt for different return levels. We found that the cumulative distribution function of the extreme electron fluxes presents a finite upper limit in (1) the core of the outer radiation belt for the lower energy channels and (2) in the inner edge of the outer radiation belt for energy channels larger than 0.653 keV. The results presented in this work are important to characterise Space Weather conditions.

scholarly journals Outer Van Allen belt trapped and precipitating electron flux responses to two interplanetary magnetic clouds of opposite polarity

2020 ◽  
Vol 38 (4) ◽  
pp. 931-951
Author(s):  
Harriet George ◽  
Emilia Kilpua ◽  
Adnane Osmane ◽  
Timo Asikainen ◽  
Milla M. H. Kalliokoski ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Radiation Belt ◽  
Magnetic Cloud ◽  
Opposite Polarity ◽  
Initial Energy ◽  
Magnetic Clouds ◽  
Interplanetary Coronal Mass Ejections ◽  
Field Orientation ◽  
Outer Radiation Belt ◽  
Trapped Electron

Abstract. Recently, it has been established that interplanetary coronal mass ejections (ICMEs) can dramatically affect both trapped electron fluxes in the outer radiation belt and precipitating electron fluxes lost from the belt into the atmosphere. Precipitating electron fluxes and energies can vary over a range of timescales during these events. These variations depend on the initial energy and location of the electron population and the ICME characteristics and structures. One important factor controlling electron dynamics is the magnetic field orientation within the ejecta that is an integral part of the ICME. In this study, we examine Van Allen Probes (RBSPs) and Polar Orbiting Environmental Satellites (POESs) data to explore trapped and precipitating electron fluxes during two ICMEs. The ejecta in the selected ICMEs have magnetic cloud characteristics that exhibit the opposite sense of the rotation of the north–south magnetic field component (BZ). RBSP data are used to study trapped electron fluxes in situ, while POES data are used for electron fluxes precipitating into the upper atmosphere. The trapped and precipitating electron fluxes are qualitatively analysed to understand their variation in relation to each other and to the magnetic cloud rotation during these events. Inner magnetospheric wave activity was also estimated using RBSP and Geostationary Operational Environmental Satellite (GOES) data. In each event, the largest changes in the location and magnitude of both the trapped and precipitating electron fluxes occurred during the southward portion of the magnetic cloud. Significant changes also occurred during the end of the sheath and at the sheath–ejecta boundary for the cloud with south to north magnetic field rotation, while the ICME with north to south rotation had significant changes at the end boundary of the cloud. The sense of rotation of BZ and its profile also clearly affects the coherence of the trapped and/or precipitating flux changes, timing of variations with respect to the ICME structures, and flux magnitude of different electron populations. The differing electron responses could therefore imply partly different dominant acceleration mechanisms acting on the outer radiation belt electron populations as a result of opposite magnetic cloud rotation.

Improving nowcasting and forecasting of the Sun-to-Belts space weather chain through the H2020 SafeSpace project

2021 ◽  
Author(s):  
Ioannis A. Daglis ◽  
Sebastien Bourdarie ◽  
Juan Cueto Rodriguez ◽  
Fabien Darrouzet ◽  
Benoit Lavraud ◽  
...  
Keyword(s):  
Space Weather ◽  
Radiation Belt ◽  
Initial Conditions ◽  
Interplanetary Space ◽  
Warning System ◽  
Environmental Indicators ◽  
The European Union ◽  
Particle Radiation ◽  
Horizon 2020 ◽  
Space Industry

<p>The H2020 SafeSpace project aims at advancing space weather nowcasting and forecasting capabilities and, ultimately, at contributing to the safety of space assets. This will be achieved through the synergy of five well-established space weather models covering the complete Sun – interplanetary space – Earth’s magnetosphere – radiation belts chain. The combined use of these models will enable the delivery of a sophisticated model of the Van Allen electron belt and of a prototype space weather service of tailored particle radiation indicators. Moreover, it will enable forecast capabilities with a target lead time of 2 to 4 days, which is a tremendous advance from current forecasts that are limited to lead times of a few hours. SafeSpace will improve radiation belt modelling through the incorporation into the Salammbô model of magnetospheric processes and parameters of critical importance to radiation belt dynamics. Furthermore, solar and interplanetary conditions will be used as initial conditions to drive the advanced radiation belt model and to provide the link to the solar origin and the interplanetary drivers of space weather. This approach will culminate in a prototype early warning system for detrimental space weather events, which will include indicators of particle radiation of use to space industry and spacecraft operators. Indicator values will be generated by the advanced radiation belt model and the performance of the prototype service will be evaluated in collaboration with space industry stakeholders. The work leading to this paper has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 870437 for the SafeSpace (Radiation Belt Environmental Indicators for the Safety of Space Assets) project.</p>

Electron Flux and Precipitation During ICME Case Studies

2020 ◽  
Author(s):  
Harriet E. George ◽  
Emilia Kilpua ◽  
Adnane Osmane ◽  
Timo Asikainen ◽  
Craig J. Rodger ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Radiation Belt ◽  
Electron Flux ◽  
Rotating Magnetic Field ◽  
Upper Atmosphere ◽  
Interplanetary Coronal Mass Ejections ◽  
Outer Radiation Belt ◽  
Magnetic Flux Ropes ◽  
Flux Ropes ◽  
Flux Response

<p>Interplanetary coronal mass ejections (ICMEs) can dramatically affect electrons in the outer radiation belt. Electron energy flux and location varies over a range of timescales during these events, depending on ICME characteristics. This highly complex response means that electron flux within the outer radiation belt and precipitation into the upper atmosphere during ICMEs is not yet fully understood. This study analyses the electron response to two ICMEs, which occurred near the maximum of Solar Cycle 24. Both ICMEs had leading shocks and sheaths, followed by magnetic flux ropes in the ejecta. The magnetic field in these flux ropes rotated throughout the events, with opposite rotation in each event. The field rotated from south to north during the first event, while the second event had rotation from north to south. Data from Van Allen Probes were used to study electron flux variation in the outer radiation belt, while POES data were used for electron precipitation into the upper atmosphere. Qualitative analysis of these data was carried out in order to characterise the temporal and spatial variations in electron flux and precipitation throughout these two events, with particular focus on the effects of the sheath and rotating magnetic field in the ICME ejecta. In both events, we observe enhanced precipitation at mid-latitudes during the southward portion of the ejecta, with greater enhancements taking place in lower energy electron populations. By contrast, flux of outer radiation belt electron populations differs significantly between the two ICMEs, highlighting the complexity of the electron flux response to these space weather events.</p>

scholarly journals Associations between Space Weather Events and the Incidence of Acute Myocardial Infarction and Deaths from Ischemic Heart Disease

Atmosphere ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 306
Author(s):  
Vidmantas Vaičiulis ◽  
Jonė Venclovienė ◽  
Abdonas Tamošiūnas ◽  
Deivydas Kiznys ◽  
Dalia Lukšienė ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Space Weather ◽  
High Speed ◽  
Geomagnetic Storms ◽  
Heart Diseases ◽  
Ischemic Heart ◽  
Human Organism ◽  
Interplanetary Coronal Mass Ejections ◽  
Weather Events

The effects of charged solar particles hitting the Earth’s magnetosphere are often harmful and can be dangerous to the human organism. The aim of this study was to analyze the associations of geomagnetic storms (GSs) and other space weather events (solar proton events (SPEs), solar flares (SFs), high-speed solar wind (HSSW), interplanetary coronal mass ejections (ICMEs) and stream interaction regions (SIRs)) with morbidity from acute myocardial infarction (AMI) and mortality from ischemic heart diseases (IHDs) during the period 2000–2015 in Kaunas (Lithuania). In 2000–2015, 12,330 AMI events (men/women n = 6942/5388) and 3742 deaths from IHD (men/women n = 2480/1262) were registered. The results showed that a higher risk of AMI and deaths from IHD were related to the period of 3 days before GS—a day after GS, and a stronger effect was observed during the spring–autumn period. The strongest effect of HSSW was observed on the day of the event. We found significant associations between the risk of AMI and death from IHD and the occurrence of SFs during GSs. We also found a statistically significant increase in rate ratios (RRs) for all AMIs and deaths from IHD between the second and fourth days of the period of ICMEs.

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