Articles | Volume 40, issue 1
https://doi.org/10.5194/angeo-40-37-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/angeo-40-37-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Regular paper
| 
25 Jan 2022
Regular paper |
| 25 Jan 2022
| 25 Jan 2022
Quantifying the non-linear dependence of energetic electron fluxes in the Earth's radiation belts with radial diffusion drivers
Adnane Osmane
CORRESPONDING AUTHOR
Department of Physics, University of Helsinki, Helsinki, Finland
Mikko Savola
Department of Physics, University of Helsinki, Helsinki, Finland
Emilia Kilpua
Department of Physics, University of Helsinki, Helsinki, Finland
Hannu Koskinen
Department of Physics, University of Helsinki, Helsinki, Finland
Joseph E. Borovsky
Space Science Institute, Boulder, CO 80301, USA
Milla Kalliokoski
Department of Physics, University of Helsinki, Helsinki, Finland
Related authors
Anton Fetzer, Mikko Savola, Adnane Osmane, Vili-Arttu Ketola, Philipp Oleynik, and Minna Palmroth
EGUsphere, https://doi.org/10.5194/egusphere-2025-1279, https://doi.org/10.5194/egusphere-2025-1279, 2025
Short summary
Short summary
Extreme events can pose serious risks to satellites, potentially disrupting communication, navigation, and power systems. Our study estimates the worst-case radiation levels during such an event and assesses their impact on electronics and solar panels.
Venla Koikkalainen, Emilia Kilpua, Simon Good, and Adnane Osmane
EGUsphere, https://doi.org/10.5194/egusphere-2025-106, https://doi.org/10.5194/egusphere-2025-106, 2025
Short summary
Short summary
We study time series of solar wind large-scale structures (magnetic clouds, sheaths, slow and fast streams). These have profound importance for causing disturbances in the heliospheric conditions and driving space weather on Earth. The used techniques include methods deriving from information theory to determine entropy and complexity. We find that all of these techniques show stochastic fluctuations, but magnetic clouds stand out due to their coherent magnetic field
Emilia K. J. Kilpua, Simon Good, Matti Ala-Lahti, Adnane Osmane, and Venla Koikkalainen
Ann. Geophys., 42, 163–177, https://doi.org/10.5194/angeo-42-163-2024, https://doi.org/10.5194/angeo-42-163-2024, 2024
Short summary
Short summary
The solar wind is organised into slow and fast streams, interaction regions, and transient structures originating from solar eruptions. Their internal characteristics are not well understood. A more comprehensive understanding of such features can give insight itno physical processes governing their formation and evolution. Using tools from information theory, we find that the solar wind shows universal turbulent properties on smaller scales, while on larger scales, clear differences arise.
Sanni Hoilijoki, Emilia Kilpua, Adnane Osmane, Lucile Turc, Mikko Savola, Veera Lipsanen, Harriet George, and Milla Kalliokoski
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2024-3, https://doi.org/10.5194/angeo-2024-3, 2024
Revised manuscript under review for ANGEO
Short summary
Short summary
Structures originating from the Sun, such as coronal mass ejections and high-speed streams, may impact the Earth's magnetosphere differently. The occurrence rate of these structures depends on the phase solar cycle. We use mutual information to study the change in the statistical dependence between solar wind and inner magnetosphere. We find that the non-linearity between solar wind and inner magnetosphere varies over the solar cycle and during different solar wind drivers.
Minna Palmroth, Savvas Raptis, Jonas Suni, Tomas Karlsson, Lucile Turc, Andreas Johlander, Urs Ganse, Yann Pfau-Kempf, Xochitl Blanco-Cano, Mojtaba Akhavan-Tafti, Markus Battarbee, Maxime Dubart, Maxime Grandin, Vertti Tarvus, and Adnane Osmane
Ann. Geophys., 39, 289–308, https://doi.org/10.5194/angeo-39-289-2021, https://doi.org/10.5194/angeo-39-289-2021, 2021
Short summary
Short summary
Magnetosheath jets are high-velocity features within the Earth's turbulent magnetosheath, separating the Earth's magnetic domain from the solar wind. The characteristics of the jets are difficult to assess statistically as a function of their lifetime because normally spacecraft observe them only at one position within the magnetosheath. This study first confirms the accuracy of the model used, Vlasiator, by comparing it to MMS spacecraft, and then carries out the first jet lifetime statistics.
Maxime Dubart, Urs Ganse, Adnane Osmane, Andreas Johlander, Markus Battarbee, Maxime Grandin, Yann Pfau-Kempf, Lucile Turc, and Minna Palmroth
Ann. Geophys., 38, 1283–1298, https://doi.org/10.5194/angeo-38-1283-2020, https://doi.org/10.5194/angeo-38-1283-2020, 2020
Short summary
Short summary
Plasma waves are ubiquitous in the Earth's magnetosphere. They are responsible for many energetic processes happening in Earth's atmosphere, such as auroras. In order to understand these processes, thorough investigations of these waves are needed. We use a state-of-the-art numerical model to do so. Here we investigate the impact of different spatial resolutions in the model on these waves in order to improve in the future the model without wasting computational resources.
Emilia K. J. Kilpua, Dominique Fontaine, Simon W. Good, Matti Ala-Lahti, Adnane Osmane, Erika Palmerio, Emiliya Yordanova, Clement Moissard, Lina Z. Hadid, and Miho Janvier
Ann. Geophys., 38, 999–1017, https://doi.org/10.5194/angeo-38-999-2020, https://doi.org/10.5194/angeo-38-999-2020, 2020
Short summary
Short summary
This paper studies magnetic field fluctuations in three turbulent sheath regions ahead of interplanetary coronal mass ejections (ICMEs) in the near-Earth solar wind. Our results show that fluctuation properties vary significantly in different parts of the sheath when compared to solar wind ahead. Turbulence in sheaths resembles that of the slow solar wind in the terrestrial magnetosheath, e.g. regarding compressibility and intermittency, and it often lacks Kolmogorov's spectral indices.
Harriet George, Emilia Kilpua, Adnane Osmane, Timo Asikainen, Milla M. H. Kalliokoski, Craig J. Rodger, Stepan Dubyagin, and Minna Palmroth
Ann. Geophys., 38, 931–951, https://doi.org/10.5194/angeo-38-931-2020, https://doi.org/10.5194/angeo-38-931-2020, 2020
Short summary
Short summary
We compared trapped outer radiation belt electron fluxes to high-latitude precipitating electron fluxes during two interplanetary coronal mass ejections (ICMEs) with opposite magnetic cloud rotation. The electron response had many similarities and differences between the two events, indicating that different acceleration mechanisms acted. Van Allen Probe data were used for trapped electron flux measurements, and Polar Operational Environmental Satellites were used for precipitating flux data.
Milla M. H. Kalliokoski, Emilia K. J. Kilpua, Adnane Osmane, Drew L. Turner, Allison N. Jaynes, Lucile Turc, Harriet George, and Minna Palmroth
Ann. Geophys., 38, 683–701, https://doi.org/10.5194/angeo-38-683-2020, https://doi.org/10.5194/angeo-38-683-2020, 2020
Short summary
Short summary
We present a comprehensive statistical study of the response of the Earth's space environment in sheath regions prior to interplanetary coronal mass ejections. The inner magnetospheric wave activity is enhanced in sheath regions, and the sheaths cause significant changes to the outer radiation belt electron fluxes over short timescales. We also show that non-geoeffective sheaths can result in a significant response.
Emilia Kilpua, Liisa Juusola, Maxime Grandin, Antti Kero, Stepan Dubyagin, Noora Partamies, Adnane Osmane, Harriet George, Milla Kalliokoski, Tero Raita, Timo Asikainen, and Minna Palmroth
Ann. Geophys., 38, 557–574, https://doi.org/10.5194/angeo-38-557-2020, https://doi.org/10.5194/angeo-38-557-2020, 2020
Short summary
Short summary
Coronal mass ejection sheaths and ejecta are key drivers of significant space weather storms, and they cause dramatic changes in radiation belt electron fluxes. Differences in precipitation of high-energy electrons from the belts to the upper atmosphere are thus expected. We investigate here differences in sheath- and ejecta-induced precipitation using the Finnish riometer (relative ionospheric opacity meter) chain.
Maxime Grandin, Markus Battarbee, Adnane Osmane, Urs Ganse, Yann Pfau-Kempf, Lucile Turc, Thiago Brito, Tuomas Koskela, Maxime Dubart, and Minna Palmroth
Ann. Geophys., 37, 791–806, https://doi.org/10.5194/angeo-37-791-2019, https://doi.org/10.5194/angeo-37-791-2019, 2019
Short summary
Short summary
When the terrestrial magnetic field is disturbed, particles from the near-Earth space can precipitate into the upper atmosphere. This work presents, for the first time, numerical simulations of proton precipitation in the energy range associated with the production of aurora (∼1–30 keV) using a global kinetic model of the near-Earth space: Vlasiator. We find that nightside proton precipitation can be regulated by the transition region between stretched and dipolar geomagnetic field lines.
Venla Koikkalainen, Maxime Grandin, Emilia Kilpua, Abiyot Workayehu, Ivan Zaitsev, Liisa Juusola, Shi Tao, Markku Alho, Lauri Pänkäläinen, Giulia Cozzani, Konstantinos Horaites, Jonas Suni, Yann Pfau-Kempf, Urs Ganse, and Minna Palmroth
EGUsphere, https://doi.org/10.5194/egusphere-2025-2265, https://doi.org/10.5194/egusphere-2025-2265, 2025
Short summary
Short summary
We use a numerical simulation to study phenomena that occur between the Earth’s dipolar magnetic field and the nightside of near-Earth space. We observe the formation of large-scale vortex flows with scales of several Earth radii. On the ionospheric grid of the simulation we find that the field-aligned currents formed in the simulation reflect the vortex flow in the transition region. The main finding is that the vortex flow is a result of a combination of flow dynamics and a plasma instability.
Anton Fetzer, Mikko Savola, Adnane Osmane, Vili-Arttu Ketola, Philipp Oleynik, and Minna Palmroth
EGUsphere, https://doi.org/10.5194/egusphere-2025-1279, https://doi.org/10.5194/egusphere-2025-1279, 2025
Short summary
Short summary
Extreme events can pose serious risks to satellites, potentially disrupting communication, navigation, and power systems. Our study estimates the worst-case radiation levels during such an event and assesses their impact on electronics and solar panels.
Venla Koikkalainen, Emilia Kilpua, Simon Good, and Adnane Osmane
EGUsphere, https://doi.org/10.5194/egusphere-2025-106, https://doi.org/10.5194/egusphere-2025-106, 2025
Short summary
Short summary
We study time series of solar wind large-scale structures (magnetic clouds, sheaths, slow and fast streams). These have profound importance for causing disturbances in the heliospheric conditions and driving space weather on Earth. The used techniques include methods deriving from information theory to determine entropy and complexity. We find that all of these techniques show stochastic fluctuations, but magnetic clouds stand out due to their coherent magnetic field
Emilia Kilpua, Simon Good, Juska Soljento, Domenico Trotta, Tia Bäcker, Julia Ruohotie, Jens Pomoell, Chaitanya Sishtla, and Rami Vainio
EGUsphere, https://doi.org/10.5194/egusphere-2024-3564, https://doi.org/10.5194/egusphere-2024-3564, 2025
Short summary
Short summary
Interplanetary shock waves are one of the major forms of heliospheric transient that can have a profound impact on solar wind plasma and magnetic field conditions and accelerate charged particles to high energies. This work performs an extensive statistical analysis to detail how some of the key solar wind turbulence parameters, critical for understanding particle acceleration, are modified at the interplanetary shocks waves.
Emilia K. J. Kilpua, Simon Good, Matti Ala-Lahti, Adnane Osmane, and Venla Koikkalainen
Ann. Geophys., 42, 163–177, https://doi.org/10.5194/angeo-42-163-2024, https://doi.org/10.5194/angeo-42-163-2024, 2024
Short summary
Short summary
The solar wind is organised into slow and fast streams, interaction regions, and transient structures originating from solar eruptions. Their internal characteristics are not well understood. A more comprehensive understanding of such features can give insight itno physical processes governing their formation and evolution. Using tools from information theory, we find that the solar wind shows universal turbulent properties on smaller scales, while on larger scales, clear differences arise.
Sanni Hoilijoki, Emilia Kilpua, Adnane Osmane, Lucile Turc, Mikko Savola, Veera Lipsanen, Harriet George, and Milla Kalliokoski
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2024-3, https://doi.org/10.5194/angeo-2024-3, 2024
Revised manuscript under review for ANGEO
Short summary
Short summary
Structures originating from the Sun, such as coronal mass ejections and high-speed streams, may impact the Earth's magnetosphere differently. The occurrence rate of these structures depends on the phase solar cycle. We use mutual information to study the change in the statistical dependence between solar wind and inner magnetosphere. We find that the non-linearity between solar wind and inner magnetosphere varies over the solar cycle and during different solar wind drivers.
Ioannis A. Daglis, Loren C. Chang, Sergio Dasso, Nat Gopalswamy, Olga V. Khabarova, Emilia Kilpua, Ramon Lopez, Daniel Marsh, Katja Matthes, Dibyendu Nandy, Annika Seppälä, Kazuo Shiokawa, Rémi Thiéblemont, and Qiugang Zong
Ann. Geophys., 39, 1013–1035, https://doi.org/10.5194/angeo-39-1013-2021, https://doi.org/10.5194/angeo-39-1013-2021, 2021
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We present a detailed account of the science programme PRESTO (PREdictability of the variable Solar–Terrestrial cOupling), covering the period 2020 to 2024. PRESTO was defined by a dedicated committee established by SCOSTEP (Scientific Committee on Solar-Terrestrial Physics). We review the current state of the art and discuss future studies required for the most effective development of solar–terrestrial physics.
Andrei Runov, Maxime Grandin, Minna Palmroth, Markus Battarbee, Urs Ganse, Heli Hietala, Sanni Hoilijoki, Emilia Kilpua, Yann Pfau-Kempf, Sergio Toledo-Redondo, Lucile Turc, and Drew Turner
Ann. Geophys., 39, 599–612, https://doi.org/10.5194/angeo-39-599-2021, https://doi.org/10.5194/angeo-39-599-2021, 2021
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In collisionless systems like space plasma, particle velocity distributions contain fingerprints of ongoing physical processes. However, it is challenging to decode this information from observations. We used hybrid-Vlasov simulations to obtain ion velocity distribution functions at different locations and at different stages of the Earth's magnetosphere dynamics. The obtained distributions provide valuable examples that may be directly compared with observations by satellites in space.
Minna Palmroth, Savvas Raptis, Jonas Suni, Tomas Karlsson, Lucile Turc, Andreas Johlander, Urs Ganse, Yann Pfau-Kempf, Xochitl Blanco-Cano, Mojtaba Akhavan-Tafti, Markus Battarbee, Maxime Dubart, Maxime Grandin, Vertti Tarvus, and Adnane Osmane
Ann. Geophys., 39, 289–308, https://doi.org/10.5194/angeo-39-289-2021, https://doi.org/10.5194/angeo-39-289-2021, 2021
Short summary
Short summary
Magnetosheath jets are high-velocity features within the Earth's turbulent magnetosheath, separating the Earth's magnetic domain from the solar wind. The characteristics of the jets are difficult to assess statistically as a function of their lifetime because normally spacecraft observe them only at one position within the magnetosheath. This study first confirms the accuracy of the model used, Vlasiator, by comparing it to MMS spacecraft, and then carries out the first jet lifetime statistics.
Maxime Dubart, Urs Ganse, Adnane Osmane, Andreas Johlander, Markus Battarbee, Maxime Grandin, Yann Pfau-Kempf, Lucile Turc, and Minna Palmroth
Ann. Geophys., 38, 1283–1298, https://doi.org/10.5194/angeo-38-1283-2020, https://doi.org/10.5194/angeo-38-1283-2020, 2020
Short summary
Short summary
Plasma waves are ubiquitous in the Earth's magnetosphere. They are responsible for many energetic processes happening in Earth's atmosphere, such as auroras. In order to understand these processes, thorough investigations of these waves are needed. We use a state-of-the-art numerical model to do so. Here we investigate the impact of different spatial resolutions in the model on these waves in order to improve in the future the model without wasting computational resources.
Emilia K. J. Kilpua, Dominique Fontaine, Simon W. Good, Matti Ala-Lahti, Adnane Osmane, Erika Palmerio, Emiliya Yordanova, Clement Moissard, Lina Z. Hadid, and Miho Janvier
Ann. Geophys., 38, 999–1017, https://doi.org/10.5194/angeo-38-999-2020, https://doi.org/10.5194/angeo-38-999-2020, 2020
Short summary
Short summary
This paper studies magnetic field fluctuations in three turbulent sheath regions ahead of interplanetary coronal mass ejections (ICMEs) in the near-Earth solar wind. Our results show that fluctuation properties vary significantly in different parts of the sheath when compared to solar wind ahead. Turbulence in sheaths resembles that of the slow solar wind in the terrestrial magnetosheath, e.g. regarding compressibility and intermittency, and it often lacks Kolmogorov's spectral indices.
Harriet George, Emilia Kilpua, Adnane Osmane, Timo Asikainen, Milla M. H. Kalliokoski, Craig J. Rodger, Stepan Dubyagin, and Minna Palmroth
Ann. Geophys., 38, 931–951, https://doi.org/10.5194/angeo-38-931-2020, https://doi.org/10.5194/angeo-38-931-2020, 2020
Short summary
Short summary
We compared trapped outer radiation belt electron fluxes to high-latitude precipitating electron fluxes during two interplanetary coronal mass ejections (ICMEs) with opposite magnetic cloud rotation. The electron response had many similarities and differences between the two events, indicating that different acceleration mechanisms acted. Van Allen Probe data were used for trapped electron flux measurements, and Polar Operational Environmental Satellites were used for precipitating flux data.
Milla M. H. Kalliokoski, Emilia K. J. Kilpua, Adnane Osmane, Drew L. Turner, Allison N. Jaynes, Lucile Turc, Harriet George, and Minna Palmroth
Ann. Geophys., 38, 683–701, https://doi.org/10.5194/angeo-38-683-2020, https://doi.org/10.5194/angeo-38-683-2020, 2020
Short summary
Short summary
We present a comprehensive statistical study of the response of the Earth's space environment in sheath regions prior to interplanetary coronal mass ejections. The inner magnetospheric wave activity is enhanced in sheath regions, and the sheaths cause significant changes to the outer radiation belt electron fluxes over short timescales. We also show that non-geoeffective sheaths can result in a significant response.
Emilia Kilpua, Liisa Juusola, Maxime Grandin, Antti Kero, Stepan Dubyagin, Noora Partamies, Adnane Osmane, Harriet George, Milla Kalliokoski, Tero Raita, Timo Asikainen, and Minna Palmroth
Ann. Geophys., 38, 557–574, https://doi.org/10.5194/angeo-38-557-2020, https://doi.org/10.5194/angeo-38-557-2020, 2020
Short summary
Short summary
Coronal mass ejection sheaths and ejecta are key drivers of significant space weather storms, and they cause dramatic changes in radiation belt electron fluxes. Differences in precipitation of high-energy electrons from the belts to the upper atmosphere are thus expected. We investigate here differences in sheath- and ejecta-induced precipitation using the Finnish riometer (relative ionospheric opacity meter) chain.
Joseph E. Borovsky and Adnane Osmane
Nonlin. Processes Geophys., 26, 429–443, https://doi.org/10.5194/npg-26-429-2019, https://doi.org/10.5194/npg-26-429-2019, 2019
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A methodology is developed to simplify the mathematical description of activity in a time-dependent driven system. The method describes the response in the system that is most-closely related to the driver. This reduced description has advantages: low noise, high prediction efficiency, linearity in the described system response to the driver, and compactness. The analysis of the Earth’s magnetospheric system is demonstrated.
Maxime Grandin, Markus Battarbee, Adnane Osmane, Urs Ganse, Yann Pfau-Kempf, Lucile Turc, Thiago Brito, Tuomas Koskela, Maxime Dubart, and Minna Palmroth
Ann. Geophys., 37, 791–806, https://doi.org/10.5194/angeo-37-791-2019, https://doi.org/10.5194/angeo-37-791-2019, 2019
Short summary
Short summary
When the terrestrial magnetic field is disturbed, particles from the near-Earth space can precipitate into the upper atmosphere. This work presents, for the first time, numerical simulations of proton precipitation in the energy range associated with the production of aurora (∼1–30 keV) using a global kinetic model of the near-Earth space: Vlasiator. We find that nightside proton precipitation can be regulated by the transition region between stretched and dipolar geomagnetic field lines.
Antti Lakka, Tuija I. Pulkkinen, Andrew P. Dimmock, Emilia Kilpua, Matti Ala-Lahti, Ilja Honkonen, Minna Palmroth, and Osku Raukunen
Ann. Geophys., 37, 561–579, https://doi.org/10.5194/angeo-37-561-2019, https://doi.org/10.5194/angeo-37-561-2019, 2019
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We study how the Earth's space environment responds to two different amplitude interplanetary coronal mass ejection (ICME) events that occurred in 2012 and 2014 by using the GUMICS-4 global MHD model. We examine local and large-scale dynamics of the Earth's space environment and compare simulation results to in situ data. It is shown that during moderate driving simulation agrees well with the measurements; however, GMHD results should be interpreted cautiously during strong driving.
Liisa Juusola, Sanni Hoilijoki, Yann Pfau-Kempf, Urs Ganse, Riku Jarvinen, Markus Battarbee, Emilia Kilpua, Lucile Turc, and Minna Palmroth
Ann. Geophys., 36, 1183–1199, https://doi.org/10.5194/angeo-36-1183-2018, https://doi.org/10.5194/angeo-36-1183-2018, 2018
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The solar wind interacts with the Earth’s magnetic field, forming a magnetosphere. On the night side solar wind stretches the magnetosphere into a long tail. A process called magnetic reconnection opens the magnetic field lines and reconnects them, accelerating particles to high energies. We study this in the magnetotail using a numerical simulation model of the Earth’s magnetosphere. We study the motion of the points where field lines reconnect and the fast flows driven by this process.
Xochitl Blanco-Cano, Markus Battarbee, Lucile Turc, Andrew P. Dimmock, Emilia K. J. Kilpua, Sanni Hoilijoki, Urs Ganse, David G. Sibeck, Paul A. Cassak, Robert C. Fear, Riku Jarvinen, Liisa Juusola, Yann Pfau-Kempf, Rami Vainio, and Minna Palmroth
Ann. Geophys., 36, 1081–1097, https://doi.org/10.5194/angeo-36-1081-2018, https://doi.org/10.5194/angeo-36-1081-2018, 2018
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We use the Vlasiator code to study the characteristics of transient structures that exist in the Earth's foreshock, i.e. upstream of the bow shock. The structures are cavitons and spontaneous hot flow anomalies (SHFAs). These transients can interact with the bow shock. We study the changes the shock suffers via this interaction. We also investigate ion distributions associated with the cavitons and SHFAs. A very important result is that the arrival of multiple SHFAs results in shock erosion.
Matti M. Ala-Lahti, Emilia K. J. Kilpua, Andrew P. Dimmock, Adnane Osmane, Tuija Pulkkinen, and Jan Souček
Ann. Geophys., 36, 793–808, https://doi.org/10.5194/angeo-36-793-2018, https://doi.org/10.5194/angeo-36-793-2018, 2018
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We present a comprehensive statistical analysis of mirror mode waves and the properties of their plasma surroundings in sheath regions driven by interplanetary coronal mass ejection (ICME) to deepen our understanding of these geo-effective plasma environments. The results imply that mirror modes are common structures in ICME sheaths and occur almost exclusively as dip-like structures and in mirror stable stable plasma.
Erika Palmerio, Emilia K. J. Kilpua, and Neel P. Savani
Ann. Geophys., 34, 313–322, https://doi.org/10.5194/angeo-34-313-2016, https://doi.org/10.5194/angeo-34-313-2016, 2016
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Coronal Mass Ejections (CMEs) are giant clouds of plasma and magnetic field that erupt from the Sun and travel though the solar wind. They can cause interplanetary shocks in the vicinity of Earth. We show in our paper that the region that follows CME-driven shocks, known as sheath region, can obtain a planar configuration of the magnetic field lines (planar magnetic structure, PMS) due to the compression resulting from the shock itself or from the draping of the magnetic field ahead of the CME.
M. Myllys, E. Kilpua, and T. Pulkkinen
Ann. Geophys., 33, 845–855, https://doi.org/10.5194/angeo-33-845-2015, https://doi.org/10.5194/angeo-33-845-2015, 2015
K. Andréeová, L. Juusola, E. K. J. Kilpua, and H. E. J. Koskinen
Ann. Geophys., 32, 1293–1302, https://doi.org/10.5194/angeo-32-1293-2014, https://doi.org/10.5194/angeo-32-1293-2014, 2014
L. Turc, D. Fontaine, P. Savoini, and E. K. J. Kilpua
Ann. Geophys., 32, 1247–1261, https://doi.org/10.5194/angeo-32-1247-2014, https://doi.org/10.5194/angeo-32-1247-2014, 2014
L. Turc, D. Fontaine, P. Savoini, and E. K. J. Kilpua
Ann. Geophys., 32, 157–173, https://doi.org/10.5194/angeo-32-157-2014, https://doi.org/10.5194/angeo-32-157-2014, 2014
D. Pokhotelov, S. von Alfthan, Y. Kempf, R. Vainio, H. E. J. Koskinen, and M. Palmroth
Ann. Geophys., 31, 2207–2212, https://doi.org/10.5194/angeo-31-2207-2013, https://doi.org/10.5194/angeo-31-2207-2013, 2013
E. K. J. Kilpua, H. Hietala, H. E. J. Koskinen, D. Fontaine, and L. Turc
Ann. Geophys., 31, 1559–1567, https://doi.org/10.5194/angeo-31-1559-2013, https://doi.org/10.5194/angeo-31-1559-2013, 2013
E. K. J. Kilpua, A. Isavnin, A. Vourlidas, H. E. J. Koskinen, and L. Rodriguez
Ann. Geophys., 31, 1251–1265, https://doi.org/10.5194/angeo-31-1251-2013, https://doi.org/10.5194/angeo-31-1251-2013, 2013
L. Turc, D. Fontaine, P. Savoini, H. Hietala, and E. K. J. Kilpua
Ann. Geophys., 31, 1011–1019, https://doi.org/10.5194/angeo-31-1011-2013, https://doi.org/10.5194/angeo-31-1011-2013, 2013
K. Andreeova, E. K. J. Kilpua, H. Hietala, H. E. J. Koskinen, A. Isavnin, and R. Vainio
Ann. Geophys., 31, 555–562, https://doi.org/10.5194/angeo-31-555-2013, https://doi.org/10.5194/angeo-31-555-2013, 2013
Related subject area
Subject: Magnetosphere & space plasma physics | Keywords: Radiation belts
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Outer Van Allen belt trapped and precipitating electron flux responses to two interplanetary magnetic clouds of opposite polarity
Outer radiation belt and inner magnetospheric response to sheath regions of coronal mass ejections: a statistical analysis
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GREEN: the new Global Radiation Earth ENvironment model (beta version)
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Alexandre Winant, Viviane Pierrard, and Edith Botek
Ann. Geophys., 41, 313–325, https://doi.org/10.5194/angeo-41-313-2023, https://doi.org/10.5194/angeo-41-313-2023, 2023
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In this work, we analyzed and compared measurements of electron fluxes in the radiation belts from two instruments with different orbits. In the outer belt, where the altitude difference is the largest between the two instruments, we find that the observations are in good agreement, except during geomagnetic storms, during which fluxes at low altitudes are much lower than at high altitudes. In general, both at low and high altitudes, the correlation between the instruments was found to be good.
Nour Dahmen, Antoine Brunet, Sebastien Bourdarie, Christos Katsavrias, Guillerme Bernoux, Stefanos Doulfis, Afroditi Nasi, Ingmar Sandberg, Constantinos Papadimitriou, Jesus Oliveros Fernandez, and Ioannis Daglis
Ann. Geophys., 41, 301–312, https://doi.org/10.5194/angeo-41-301-2023, https://doi.org/10.5194/angeo-41-301-2023, 2023
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Earth’s space environment is populated with charged particles. The energetic ones are trapped around Earth in radiation belts. Orbiting spacecraft that cross their region can accumulate charges on their internal surfaces, leading to hazardous electrostatic discharges. This paper showcases the SafeSpace safety prototype, which aims to warn satellite operators of probable incoming hazardous events by simulating the dynamics of the electron radiation belts from their origin at the Sun.
Christos Katsavrias, Afroditi Nasi, Ioannis A. Daglis, Sigiava Aminalragia-Giamini, Nourallah Dahmen, Constantinos Papadimitriou, Marina Georgiou, Antoine Brunet, and Sebastien Bourdarie
Ann. Geophys., 40, 379–393, https://doi.org/10.5194/angeo-40-379-2022, https://doi.org/10.5194/angeo-40-379-2022, 2022
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The radial diffusion mechanism is of utmost importance to both the acceleration and loss of relativistic electrons in the outer radiation belt and, consequently, for physics-based models, which provide nowcasting and forecasting of the electron population. In the framework of the "SafeSpace" project, we have created a database of calculated radial diffusion coefficients, and, furthermore, we have exploited it to provide insights for future modelling efforts.
Christos Katsavrias, Constantinos Papadimitriou, Sigiava Aminalragia-Giamini, Ioannis A. Daglis, Ingmar Sandberg, and Piers Jiggens
Ann. Geophys., 39, 413–425, https://doi.org/10.5194/angeo-39-413-2021, https://doi.org/10.5194/angeo-39-413-2021, 2021
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The nature of the semi-annual variation in the relativistic electron fluxes in the Earth's outer radiation belt has been a debate for over 30 years. Our work shows that it is primarily driven by the Russell–McPherron effect, which indicates that reconnection is responsible not only for the short-scale but also the seasonal variability of the electron belt as well. Moreover, it is more pronounced during the descending phase of the solar cycles and coexists with periods of fast solar wind speed.
Rajkumar Hajra
Ann. Geophys., 39, 181–187, https://doi.org/10.5194/angeo-39-181-2021, https://doi.org/10.5194/angeo-39-181-2021, 2021
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Geomagnetic activity is known to exhibit semi-annual variation with larger occurrences during equinoxes. A similar seasonal feature was reported for relativistic (∼ MeV) electrons throughout the entire outer zone radiation belt. Present work, for the first time reveals that electron fluxes increase with an ∼ 6-month periodicity in a limited L-shell only with large dependence in solar activity cycle. In addition, flux enhancements are not essentially equinoctial.
Alexander S. Kovtyukh
Ann. Geophys., 39, 171–179, https://doi.org/10.5194/angeo-39-171-2021, https://doi.org/10.5194/angeo-39-171-2021, 2021
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This is a continuation of work published in Annales Gephysicae between 2016 and 2020. In this paper, a new method for analyzing experimental data is proposed, calculations are carried out, and a new class of distributions of particles of radiation belts is constructed. As a result of this work, new, finer physical regularities of the structure of the Earth's proton radiation belt and its solar-cyclic variations have been obtained, which cannot be obtained by other methods.
Harriet George, Emilia Kilpua, Adnane Osmane, Timo Asikainen, Milla M. H. Kalliokoski, Craig J. Rodger, Stepan Dubyagin, and Minna Palmroth
Ann. Geophys., 38, 931–951, https://doi.org/10.5194/angeo-38-931-2020, https://doi.org/10.5194/angeo-38-931-2020, 2020
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We compared trapped outer radiation belt electron fluxes to high-latitude precipitating electron fluxes during two interplanetary coronal mass ejections (ICMEs) with opposite magnetic cloud rotation. The electron response had many similarities and differences between the two events, indicating that different acceleration mechanisms acted. Van Allen Probe data were used for trapped electron flux measurements, and Polar Operational Environmental Satellites were used for precipitating flux data.
Milla M. H. Kalliokoski, Emilia K. J. Kilpua, Adnane Osmane, Drew L. Turner, Allison N. Jaynes, Lucile Turc, Harriet George, and Minna Palmroth
Ann. Geophys., 38, 683–701, https://doi.org/10.5194/angeo-38-683-2020, https://doi.org/10.5194/angeo-38-683-2020, 2020
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We present a comprehensive statistical study of the response of the Earth's space environment in sheath regions prior to interplanetary coronal mass ejections. The inner magnetospheric wave activity is enhanced in sheath regions, and the sheaths cause significant changes to the outer radiation belt electron fluxes over short timescales. We also show that non-geoeffective sheaths can result in a significant response.
Alla V. Suvorova, Alexei V. Dmitriev, and Vladimir A. Parkhomov
Ann. Geophys., 37, 1223–1241, https://doi.org/10.5194/angeo-37-1223-2019, https://doi.org/10.5194/angeo-37-1223-2019, 2019
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The Earth's radiation belts control the space environment, often affecting the GPS signal propagation and satellite operations. Intense fluxes of energetic particles can penetrate even below the inner belt near the Equator. We analysed electron penetrations under geomagnetic quiet conditions and found in the solar wind an external driver cause. Satellite observations prove that disturbance of the inner belt was associated with impact of plasma jets formed in the solar wind nearby the Earth.
Angélica Sicard, Daniel Boscher, Sébastien Bourdarie, Didier Lazaro, Denis Standarovski, and Robert Ecoffet
Ann. Geophys., 36, 953–967, https://doi.org/10.5194/angeo-36-953-2018, https://doi.org/10.5194/angeo-36-953-2018, 2018
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GREEN (Global Radiation Earth ENvironment) is a new model providing particle fluxes at any location in the radiation belts, for energy between 1 keV
and 10 MeV for electrons and between 1 keV and 800 MeV for protons. This model is composed of global models (AE8 and AP8, and SPM) and
local models (SLOT model, OZONE and IGE-2006 for electrons; OPAL and IGP for protons).
Run Shi, Wen Li, Qianli Ma, Seth G. Claudepierre, Craig A. Kletzing, William S. Kurth, George B. Hospodarsky, Harlan E. Spence, Geoff D. Reeves, Joseph F. Fennell, J. Bernard Blake, Scott A. Thaller, and John R. Wygant
Ann. Geophys., 36, 781–791, https://doi.org/10.5194/angeo-36-781-2018, https://doi.org/10.5194/angeo-36-781-2018, 2018
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Short summary
It has long been known that particles get accelerated close to the speed of light in the near-Earth space environment. Research in the last decades has also clarified what processes and waves are responsible for the acceleration of particles. However, it is difficult to quantify the scale of the impact of various processes competing with one another. In this study we present a methodology to quantify the impact waves can have on energetic particles.
It has long been known that particles get accelerated close to the speed of light in the...
