A5071399251- Ionosphere and magnetosphere dynamics
- Solar and Space Plasma Dynamics
- Earthquake Detection and Analysis
- Seismic Waves and Analysis
- Geomagnetism and Paleomagnetism Studies
- Atmospheric Ozone and Climate
- Methane Hydrates and Related Phenomena
- Seismic Imaging and Inversion Techniques
- Risk and Safety Analysis
- Meteorological Phenomena and Simulations
National and Kapodistrian University of Athens
2020-2024
National Centre of Scientific Research "Demokritos"
2022
Radial diffusion in planetary radiation belts is a dominant transport mechanism resulting the energization and losses of chargedparticles by large-scale electromagnetic fluctuations. In this work we exploit extensive radial coefficients (DLL) database createdin framework Horizon 2020 SafeSpace project, which spans 9 years hourly DLL coefficients, to investigate spatiotemporaldistributions coefficients. Our results indicate that distribution magnetic electric component theDLL, as well their...
Abstract. Radial diffusion has been established as one of the most important mechanisms contributing to both acceleration and loss relativistic electrons in outer radiation belt, well supply particles inner belt. In framework “SafeSpace” project, we have used 9 years (2011–2019) multi-point magnetic electric field measurements from THEMIS A, D E satellites create a database radial coefficients (DLL) ultra-low-frequency (ULF) wave power spectral densities (PSDs) spanning an L∗ range 3 8. this...
Abstract The H2020 SafeSpace project aims at the implementation of a space weather safety prototype, in particular to predict deep charging hazard. proposed service is built on Sun‐to‐Earth chain physical codes that propagates information and uncertainties order model outer radiation belt dynamics. In this paper, we present inner magnetosphere section pipeline relies solar wind driven hourly updated models describe trapped electron environment (VLF waves, cold plasma seed population...
During July to October of 2019, a sequence isolated Corotating Interaction Regions (CIRs) impacted the magnetosphere, for four consecutive solar rotations, without any interposed Interplanetary Coronal Mass Ejections. Even though series CIRs resulted in relatively weak geomagnetic storms, net effect outer radiation belt during each disturbance was different, depending on electron energy. August-September CIR group, significant multi-MeV enhancements occurred, up ultra-relativistic energies...
Abstract. In this paper, we present the SafeSpace prototype for a safety warning system, dedicated to electron radiation-belt-induced internal charging hazard aboard spacecraft. The space weather tool relies on synergy of physical models associated in chain that covers whole Sun–interplanetary-space–Earth's inner magnetosphere medium. With propagation uncertainties along modelling pipeline, provides global nowcast and forecast (within 4 d lead time) radiation belt dynamic as well tailored...
Abstract Radial diffusion is one of the dominant physical mechanisms driving acceleration and loss electrons in outer radiation belt. Therefore, accurate estimation radial coefficients ( D LL ) crucial for detailed belt modeling. In recent years several semi‐empirical (SE) models have been developed which predominantly rely on parameterizations Kp index. However, studies suggested that estimations derived from such can large deviations actual (measurement derived) values. this work we used...
Radial diffusion, driven by Ultra-Low Frequency (ULF) waves in the Pc4–5 band (2–25 mHz), has been established as one of most important mechanisms that influences dynamics electrons a quite broad energy range, it can lead to both energization and loss relativistic outer Van Allen radiation belt. The same observed other planetary magnetospheres. dependence ULF wave power spectral density radial diffusion coefficients (DLL) on solar wind parameters investigated some...
Abstract. In this paper, we present the SafeSpace prototype for a safety warning system, dedicated to electron-radiation-belt induced internal charging hazard, aboard spacecraft. The space weather tool relies on synergy of physical models associated in chain that covers whole Sun-interplanetary space-Earth's inner magnetosphere medium. With propagation uncertainties along modelling pipeline, provides global nowcast and forecast (within 4-day lead time) electron radiation belt dynamic as well...
<p>Radial diffusion driven by Ultra Low Frequency (ULF) waves is very important for magnetospheric dynamics, because it contributes to relativistic electron enhancements and losses in the outer Van Allen radiation belt. Previous studies have investigated dependence of ULF wave power spectral density radial coefficients (D<sub>LL</sub>) on solar wind parameters. However, a conclusive correlation between type interplanetary drivers (such as...
<p>Radial diffusion has been established as one of the most important mechanisms contributing acceleration and loss relativistic electrons in outer radiation belt. Over past few years efforts have devoted to provide empirical relationships radial coefficients (D<sub>LL</sub>) for belt simulations yet several studies suggested that difference between various models can be orders magnitude different at high levels geomagnetic activity observed...
Abstract. Radial diffusion has been established as one of the most important mechanisms contributing to both acceleration and loss relativistic electrons in outer radiation belt. In framework SafeSpace project we have used 9 years (2011–2019) multi-point magnetic electric field measurements from THEMIS A, D E satellites create a database accurately calculated radial coefficients (DLL) spanning an L* range 3 8. this work investigate dependence DLL on various solar wind parameters, geomagnetic...
During the second half of 2019, Earth’s magnetosphere was impacted by a sequence Corotating Interaction Regions (CIRs) during four consecutive solar rotations. Based on wind properties, CIRs can be divided in groups, with 3rd group, which arrived August-September resulting significant multi-MeV electron enhancements, up to ultra-relativistic energies 9.9 MeV.Each CIR group has different effect outer radiation belt populations; we investigate them exploiting combined measurements...
The outer Van Allen radiation belt stands out for its intense variability, due to the complex mechanisms that take place Sun – Earth coupling. One fundamentally important effect is acceleration of seed electrons relativistic and ultra energies, through different mechanisms, namely radial diffusion local acceleration.In our work, we examine 46 events from Probes era (2012 2018), which categorize according interplanetary driver geomagnetic disturbance. In particular, study 16 caused...
The European SafeSpace project has implemented a synergistical approach to improve space weather forecasting capabilities from the current lead times of few hours 2-4 days. We have combined solar wind acceleration model MULTI-VP with heliospheric propagation models Helio1D and EUHFORIA compute evolution surface Sun Earth orbit. forecasted conditions are then fed into ONERA Geoffectiveness Neural Network, forecast level geomagnetic activity Kp index as chosen proxy. is used input parameter...
<p>The energetic particles of the outer radiation belt are highly variable in space, time and energy, due to complex interplay between various mechanisms that contribute their energization and/or loss. Previous studies have focused on influence solar wind magnetospheric processes electron population dynamics, showing eventual effect interplanetary drivers results from different combinations IMF parameters. Yet, all these were limited temporal, spatial energy coverage. In this...
<p>Local acceleration driven by whistler-mode chorus waves is fundamentally important for the of seed electrons in outer radiation belt to relativistic energies. Τhis mechanism strongly depends on substorm activity and source electron population injected substorms into inner magnetosphere. In our work we use Van Allen Probes data investigate features electrons, events enhancement versus depletion belt. To that end calculate phase space density (PSD) five values...
<p>During July-October of 2019, a sequence Corotating Interaction Regions (V<sub>SW</sub> ≥ 600 km/s) impacted the magnetosphere, for four consecutive solar rotations. Even though series CIRs resulted in relatively weak geomagnetic storms (SYM-H<sub>min</sub> ≈ -60 nT, Kp<sub>max</sub> 5), net effect outer radiation belt during each disturbance was different,...
<p>Radial diffusion has been established as one of the most important mechanisms contributing to acceleration and loss relativistic electrons in outer radiation belt. Over past few years efforts have devoted identify empirical relationships radial coefficients (D<sub>LL</sub>) for belt simulations, yet several studies suggested that difference between various models can be orders magnitude different at high levels geomagnetic activity, observed DLL...
<p>During the second half of 2019, a sequence solar wind high-speed streams (V<sub>SW</sub> ≥ 600 km/s)  impacted magnetosphere, resulting in series recurrent, relatively weak, geomagnetic storms (Dst<sub>min</sub> - 80 nT). During one these storms, longer-lasting pressure pulse and intense substorm activity were also recorded (AL ≤ 1600 nT on August 31 September...