Articles | Volume 36, issue 4
https://doi.org/10.5194/angeo-36-1081-2018
© Author(s) 2018. 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-36-1081-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Regular paper
| 
08 Aug 2018
Regular paper |
| 08 Aug 2018
| 08 Aug 2018
Cavitons and spontaneous hot flow anomalies in a hybrid-Vlasov global magnetospheric simulation
Xochitl Blanco-Cano
CORRESPONDING AUTHOR
Instituto de Geofisica, Universidad Nacional Autonoma de Mexico, Mexico City, Mexico
Markus Battarbee
Department of Physics, University of Helsinki, Helsinki, Finland
Lucile Turc
Department of Physics, University of Helsinki, Helsinki, Finland
Andrew P. Dimmock
Swedish Institute of Space Physics, Uppsala, Sweden
Department of Electronics and Nanoengineering, School of Electrical Engineering, Aalto University, Espoo, Finland
Emilia K. J. Kilpua
Department of Physics, University of Helsinki, Helsinki, Finland
Sanni Hoilijoki
Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, USA
Urs Ganse
Department of Physics, University of Helsinki, Helsinki, Finland
David G. Sibeck
NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
Paul A. Cassak
Department of Physics and Astronomy, West Virginia University, Morgantown, West Virginia, USA
Robert C. Fear
Department of Physics and Astronomy, University of Southampton, Southampton, UK
Riku Jarvinen
Department of Electronics and Nanoengineering, School of Electrical Engineering, Aalto University, Espoo, Finland
Finnish Meteorological Institute, Helsinki, Finland
Liisa Juusola
Finnish Meteorological Institute, Helsinki, Finland
Department of Physics, University of Helsinki, Helsinki, Finland
Yann Pfau-Kempf
Department of Physics, University of Helsinki, Helsinki, Finland
Rami Vainio
Department of Physics and Astronomy, University of Turku, Turku, Finland
Minna Palmroth
Department of Physics, University of Helsinki, Helsinki, Finland
Finnish Meteorological Institute, Helsinki, Finland
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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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Vertti Tarvus, Lucile Turc, Markus Battarbee, Jonas Suni, Xóchitl Blanco-Cano, Urs Ganse, Yann Pfau-Kempf, Markku Alho, Maxime Dubart, Maxime Grandin, Andreas Johlander, Konstantinos Papadakis, and Minna Palmroth
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We use simulations of Earth's magnetosphere and study the formation of transient wave structures in the region where the solar wind first interacts with the magnetosphere. These transients move earthward and play a part in the solar wind–magnetosphere interaction. We show that the transients are a common feature and their properties are altered as they move earthward, including an increase in temperature, decrease in solar wind speed and an alteration in their propagation properties.
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
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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
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Markus Battarbee, Thiago Brito, Markku Alho, Yann Pfau-Kempf, Maxime Grandin, Urs Ganse, Konstantinos Papadakis, Andreas Johlander, Lucile Turc, Maxime Dubart, and Minna Palmroth
Ann. Geophys., 39, 85–103, https://doi.org/10.5194/angeo-39-85-2021, https://doi.org/10.5194/angeo-39-85-2021, 2021
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We investigate local acceleration dynamics of electrons with a new numerical simulation method, which is an extension of a world-leading kinetic plasma simulation. We describe how large supercomputer simulations can be used to initialize the electron simulations and show numerical stability for the electron method. We show that features of our simulated electrons match observations from Earth's magnetic tail region.
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
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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.
Galina Korotova, David Sibeck, Mark Engebretson, Michael Balikhin, Scott Thaller, Craig Kletzing, Harlan Spence, and Robert Redmon
Ann. Geophys., 38, 1267–1281, https://doi.org/10.5194/angeo-38-1267-2020, https://doi.org/10.5194/angeo-38-1267-2020, 2020
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We used multipoint magnetic field, electric field, plasma, and energetic particle observations to study the spatial, temporal, and spectral characteristics of compressional Pc5 pulsations observed deep within the magnetosphere at the end of a strong magnetic storm. We investigated the mode of the waves and their nodal structure. The energetic particles responded directly to the compressional Pc5 pulsations. We interpret the compressional Pc5 waves in terms of drift-mirror instability.
Markus Battarbee, Xóchitl Blanco-Cano, Lucile Turc, Primož Kajdič, Andreas Johlander, Vertti Tarvus, Stephen Fuselier, Karlheinz Trattner, Markku Alho, Thiago Brito, Urs Ganse, Yann Pfau-Kempf, Mojtaba Akhavan-Tafti, Tomas Karlsson, Savvas Raptis, Maxime Dubart, Maxime Grandin, Jonas Suni, and Minna Palmroth
Ann. Geophys., 38, 1081–1099, https://doi.org/10.5194/angeo-38-1081-2020, https://doi.org/10.5194/angeo-38-1081-2020, 2020
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We investigate the dynamics of helium in the foreshock, a part of near-Earth space found upstream of the Earth's bow shock. We show how the second most common ion in interplanetary space reacts strongly to plasma waves found in the foreshock. Spacecraft observations and supercomputer simulations both give us a new understanding of the foreshock edge and how to interpret future observations.
Lucile Turc, Vertti Tarvus, Andrew P. Dimmock, Markus Battarbee, Urs Ganse, Andreas Johlander, Maxime Grandin, Yann Pfau-Kempf, Maxime Dubart, and Minna Palmroth
Ann. Geophys., 38, 1045–1062, https://doi.org/10.5194/angeo-38-1045-2020, https://doi.org/10.5194/angeo-38-1045-2020, 2020
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Using global computer simulations, we study properties of the magnetosheath, the region of near-Earth space where the stream of particles originating from the Sun, the solar wind, is slowed down and deflected around the Earth's magnetic field. One of our main findings is that even for idealised solar wind conditions as used in our model, the magnetosheath density shows large-scale spatial and temporal variation in the so-called quasi-parallel magnetosheath, causing varying levels of asymmetry.
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
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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
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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.
Markus Battarbee, Urs Ganse, Yann Pfau-Kempf, Lucile Turc, Thiago Brito, Maxime Grandin, Tuomas Koskela, and Minna Palmroth
Ann. Geophys., 38, 625–643, https://doi.org/10.5194/angeo-38-625-2020, https://doi.org/10.5194/angeo-38-625-2020, 2020
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The structure and medium-scale dynamics of Earth's bow shock and how charged solar wind particles are reflected by it are studied in order to better understand space weather effects. We use advanced supercomputer simulations to model the shock and reflected ions. We find that the thickness of the shock depends on solar wind conditions but also has small-scale variations. Charged particle reflection is shown to be non-localized. Magnetic fields are important for ion reflection.
Theodoros E. Sarris, Elsayed R. Talaat, Minna Palmroth, Iannis Dandouras, Errico Armandillo, Guram Kervalishvili, Stephan Buchert, Stylianos Tourgaidis, David M. Malaspina, Allison N. Jaynes, Nikolaos Paschalidis, John Sample, Jasper Halekas, Eelco Doornbos, Vaios Lappas, Therese Moretto Jørgensen, Claudia Stolle, Mark Clilverd, Qian Wu, Ingmar Sandberg, Panagiotis Pirnaris, and Anita Aikio
Geosci. Instrum. Method. Data Syst., 9, 153–191, https://doi.org/10.5194/gi-9-153-2020, https://doi.org/10.5194/gi-9-153-2020, 2020
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Daedalus aims to measure the largely unexplored area between Eart's atmosphere and space, the Earth's
ignorosphere. Here, intriguing and complex processes govern the deposition and transport of energy. The aim is to quantify this energy by measuring effects caused by electrodynamic processes in this region. The concept is based on a mother satellite that carries a suite of instruments, along with smaller satellites carrying a subset of instruments that are released into the atmosphere.
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
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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
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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.
Minna Palmroth, Heli Hietala, Ferdinand Plaschke, Martin Archer, Tomas Karlsson, Xóchitl Blanco-Cano, David Sibeck, Primož Kajdič, Urs Ganse, Yann Pfau-Kempf, Markus Battarbee, and Lucile Turc
Ann. Geophys., 36, 1171–1182, https://doi.org/10.5194/angeo-36-1171-2018, https://doi.org/10.5194/angeo-36-1171-2018, 2018
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Magnetosheath jets are high-velocity plasma structures that are commonly observed within the Earth's magnetosheath. Previously, they have mainly been investigated with spacecraft observations, which do not allow us to infer their spatial sizes, temporal evolution, or origin. This paper shows for the first time their dimensions, evolution, and origins within a simulation whose dimensions are directly comparable to the Earth's magnetosphere. The results are compared to previous observations.
Yaireska M. Collado-Vega, Virginia L. Kalb, David G. Sibeck, Kyoung-Joo Hwang, and Lutz Rastätter
Ann. Geophys., 36, 1117–1129, https://doi.org/10.5194/angeo-36-1117-2018, https://doi.org/10.5194/angeo-36-1117-2018, 2018
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This paper describes an algorithm that automatically detects vortices around the Earth's magnetosphere using the velocity field from simulated data. It also describes how the tool can be used to analyze further properties of the vortices including the velocity changes within their motion across the magnetosheath. Vortices developed at the magnetopause boundary contribute to the process of mass, momentum and energy transfer from the solar wind into the Earth's magnetosphere.
Liisa Juusola, Yann Pfau-Kempf, Urs Ganse, Markus Battarbee, Thiago Brito, Maxime Grandin, Lucile Turc, and Minna Palmroth
Ann. Geophys., 36, 1027–1035, https://doi.org/10.5194/angeo-36-1027-2018, https://doi.org/10.5194/angeo-36-1027-2018, 2018
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The Earth's magnetic field is shaped by the solar wind. On the dayside the field is compressed and on the nightside it is stretched as a long tail. The tail has been observed to occasionally undergo flapping motions, but the origin of these motions is not understood. We study the flapping using a numerical simulation of the near-Earth space. We present a possible explanation for how the flapping could be initiated by a passing disturbance and then maintained as a standing wave.
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.
Minna Palmroth, Sanni Hoilijoki, Liisa Juusola, Tuija I. Pulkkinen, Heli Hietala, Yann Pfau-Kempf, Urs Ganse, Sebastian von Alfthan, Rami Vainio, and Michael Hesse
Ann. Geophys., 35, 1269–1274, https://doi.org/10.5194/angeo-35-1269-2017, https://doi.org/10.5194/angeo-35-1269-2017, 2017
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Much like solar flares, substorms occurring within the Earth's magnetic domain are explosive events that cause vivid auroral displays. A decades-long debate exists to explain the substorm onset. We devise a simulation encompassing the entire near-Earth space and demonstrate that detailed modelling of magnetic reconnection explains the central substorm observations. Our results help to understand the unpredictable substorm process, which will significantly improve space weather forecasts.
Antti Lakka, Tuija I. Pulkkinen, Andrew P. Dimmock, Adnane Osmane, Ilja Honkonen, Minna Palmroth, and Pekka Janhunen
Ann. Geophys., 35, 907–922, https://doi.org/10.5194/angeo-35-907-2017, https://doi.org/10.5194/angeo-35-907-2017, 2017
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We studied the impact on global MHD simulations from different simulation initialisation methods. While the global MHD code used is GUMICS-4 we conclude that the results might be generalisable to other codes as well. It is found that different initialisation methods affect the dynamics of the Earth's space environment by creating differences in momentum transport several hours afterwards. These differences may even grow as a response to rapid solar wind condition changes.
Christina Chu, Hui Zhang, David Sibeck, Antonius Otto, QiuGang Zong, Nick Omidi, James P. McFadden, Dennis Fruehauff, and Vassilis Angelopoulos
Ann. Geophys., 35, 443–451, https://doi.org/10.5194/angeo-35-443-2017, https://doi.org/10.5194/angeo-35-443-2017, 2017
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Hot flow anomalies (HFAs) at Earth's bow shock were identified in Time History of Events and Macroscale Interactions During Substorms (THEMIS) satellite data from 2007 to 2009. The events were classified as young or mature and regular or spontaneous hot flow anomalies (SHFAs). HFA–SHFA occurrence decreases with distance upstream from the bow shock. HFAs are more prevalent for radial interplanetary magnetic fields and solar wind speeds from 550 to 600 kms−1.
Galina Korotova, David Sibeck, Mark Engebretson, John Wygant, Scott Thaller, Harlan Spence, Craig Kletzing, Vassilis Angelopoulos, and Robert Redmon
Ann. Geophys., 34, 985–998, https://doi.org/10.5194/angeo-34-985-2016, https://doi.org/10.5194/angeo-34-985-2016, 2016
Yann Pfau-Kempf, Heli Hietala, Steve E. Milan, Liisa Juusola, Sanni Hoilijoki, Urs Ganse, Sebastian von Alfthan, and Minna Palmroth
Ann. Geophys., 34, 943–959, https://doi.org/10.5194/angeo-34-943-2016, https://doi.org/10.5194/angeo-34-943-2016, 2016
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We have simulated the interaction of the solar wind – the charged particles and magnetic fields emitted by the Sun into space – with the magnetic field of the Earth. The solar wind flows supersonically and creates a shock when it encounters the obstacle formed by the geomagnetic field. We have identified a new chain of events which causes phenomena in the downstream region to eventually cause perturbations at the shock and even upstream. This is confirmed by ground and satellite observations.
Andrew P. Dimmock, Tuija I. Pulkkinen, Adnane Osmane, and Katariina Nykyri
Ann. Geophys., 34, 511–528, https://doi.org/10.5194/angeo-34-511-2016, https://doi.org/10.5194/angeo-34-511-2016, 2016
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Ion densities measured on the dawn-side magnetosheath flank were higher than the dusk-flank. The asymmetry was measured close to the magnetopause, but it became more ambiguous in the central magnetosheath. We show that the asymmetry was at its maximum at the 2009 solar minimum (~ 20 %), but then decreased in the rising stage of the next solar cycle (< 5 %). These results could impact plasma transport processes which are dependent on local magnetopause conditions such as Kelvin Helmholtz Instability.
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.
G. I. Korotova, D. G. Sibeck, K. Tahakashi, L. Dai, H. E. Spence, C. A. Kletzing, J. R. Wygant, J. W. Manweiler, P. S. Moya, K.-J. Hwang, and R. J. Redmon
Ann. Geophys., 33, 955–964, https://doi.org/10.5194/angeo-33-955-2015, https://doi.org/10.5194/angeo-33-955-2015, 2015
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We studied localized Pc 4 pulsations in the pre-midnight inner magnetosphere observed by Van Allen Probe B on May 1 2013. Although we attribute the pulsations to a drift-bounce resonance, we demonstrate that the energy-dependent response of the ion fluxes result from pulsation-associated velocities sweeping energy-dependent radial ion flux gradients back and forth past the spacecraft.
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
P. T. Verronen, M. E. Andersson, A. Kero, C.-F. Enell, J. M. Wissing, E. R. Talaat, K. Kauristie, M. Palmroth, T. E. Sarris, and E. Armandillo
Ann. Geophys., 33, 381–394, https://doi.org/10.5194/angeo-33-381-2015, https://doi.org/10.5194/angeo-33-381-2015, 2015
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Electron concentrations observed by EISCAT radars can be reasonable well represented using AIMOS v1.2 satellite-data-based ionization model and SIC D-region ion chemistry model. SIC-EISCAT difference varies from event to event, probably because the statistical nature of AIMOS ionization is not capturing all the spatio-temporal fine structure of electron precipitation. Below 90km, AIMOS overestimates electron ionization because of proton contamination of the satellite electron detectors.
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
P. Kajdič, X. Blanco-Cano, N. Omidi, K. Meziane, C. T. Russell, J.-A. Sauvaud, I. Dandouras, and B. Lavraud
Ann. Geophys., 31, 2163–2178, https://doi.org/10.5194/angeo-31-2163-2013, https://doi.org/10.5194/angeo-31-2163-2013, 2013
F. R. Cardoso, W. D. Gonzalez, D. G. Sibeck, M. Kuznetsova, and D. Koga
Ann. Geophys., 31, 1853–1866, https://doi.org/10.5194/angeo-31-1853-2013, https://doi.org/10.5194/angeo-31-1853-2013, 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
Y. M. Collado-Vega, R. L. Kessel, D. G. Sibeck, V. L. Kalb, R. A. Boller, and L. Rastaetter
Ann. Geophys., 31, 1463–1483, https://doi.org/10.5194/angeo-31-1463-2013, https://doi.org/10.5194/angeo-31-1463-2013, 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
A. T. Aikio, T. Pitkänen, I. Honkonen, M. Palmroth, and O. Amm
Ann. Geophys., 31, 1021–1034, https://doi.org/10.5194/angeo-31-1021-2013, https://doi.org/10.5194/angeo-31-1021-2013, 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: Bow shock and foreshock
Short Large-Amplitude Magnetic Structures (SLAMS) at Mercury observed by MESSENGER
Fine structure and motion of the bow shock and particle energisation mechanisms inferred from Magnetospheric Multiscale (MMS) observations
Foreshock cavitons and spontaneous hot flow anomalies: a statistical study with a global hybrid-Vlasov simulation
Evidence of the nonstationarity of the terrestrial bow shock from multi-spacecraft observations: methodology, results, and quantitative comparison with particle-in-cell (PIC) simulations
A deep insight into the ion foreshock with the help of test particle two-dimensional simulations
Helium in the Earth's foreshock: a global Vlasiator survey
Non-locality of Earth's quasi-parallel bow shock: injection of thermal protons in a hybrid-Vlasov simulation
Low-frequency magnetic variations at the high-β Earth bow shock
Comment on “Cavitons and spontaneous hot flow anomalies in a hybrid-Vlasov global magnetospheric simulation” by Blanco-Cano et al. (2018)
Reflection of the strahl within the foot of the Earth's bow shock
Tomas Karlsson, Ferdinand Plaschke, Austin N. Glass, and Jim M. Raines
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2023-13, https://doi.org/10.5194/angeo-2023-13, 2023
Revised manuscript accepted for ANGEO
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The solar wind interacts with the planets in the solar system, and creates a supersonic shock in front of them. The upstream region of this shock contains many complicated phenomena. One such phenomenon is small-scale structures of strong magnetic fields (SLAMS). These SLAMS have been observed at Earth, and are important in determining the properties of space around the planet. Until now SLAMS have not been observed at Mercury, but we here show for the first time that SLAMS exist also here.
Krzysztof Stasiewicz and Zbigniew Kłos
Ann. Geophys., 40, 315–325, https://doi.org/10.5194/angeo-40-315-2022, https://doi.org/10.5194/angeo-40-315-2022, 2022
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The acceleration, or energisation, of particles is a common and fundamental process throughout the universe. This study presents new observations of the acceleration of protons by waves at the bow shock upstream of the Earth, where the solar wind first encounters Earth’s magnetic field. The results are important, because they provide insight into acceleration processes that can create high-energy particles both near the Earth and at other astrophysical systems.
Vertti Tarvus, Lucile Turc, Markus Battarbee, Jonas Suni, Xóchitl Blanco-Cano, Urs Ganse, Yann Pfau-Kempf, Markku Alho, Maxime Dubart, Maxime Grandin, Andreas Johlander, Konstantinos Papadakis, and Minna Palmroth
Ann. Geophys., 39, 911–928, https://doi.org/10.5194/angeo-39-911-2021, https://doi.org/10.5194/angeo-39-911-2021, 2021
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We use simulations of Earth's magnetosphere and study the formation of transient wave structures in the region where the solar wind first interacts with the magnetosphere. These transients move earthward and play a part in the solar wind–magnetosphere interaction. We show that the transients are a common feature and their properties are altered as they move earthward, including an increase in temperature, decrease in solar wind speed and an alteration in their propagation properties.
Christian Mazelle and Bertrand Lembège
Ann. Geophys., 39, 571–598, https://doi.org/10.5194/angeo-39-571-2021, https://doi.org/10.5194/angeo-39-571-2021, 2021
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Nonstationarity of the quasi-perpendicular terrestrial bow shock is analyzed from magnetic field measurements, comparison with 2D particle-in-cell (PIC) simulations, and a careful and accurate methodology in the data processing. The results show evidence of a strong variability of the microstructures of the shock front (foot and ramp), confirming the importance of dissipative effects. These results indicate that these features can be signatures of the shock front self-reformation.
Philippe Savoini and Bertrand Lembège
Ann. Geophys., 38, 1217–1235, https://doi.org/10.5194/angeo-38-1217-2020, https://doi.org/10.5194/angeo-38-1217-2020, 2020
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Numerical simulations have been used to investigate some acceleration mechanisms in order to explain the origin of the energized back-streaming ions observed at the Earth's bow shock. This paper used test particles in two different configurations with self-consistent and fixed shock front profiles. The comparison of these two configurations allows us to analyze, in detail, the impact of the shock front nonstationarity and the role of the built-up electric field in the acceleration process.
Markus Battarbee, Xóchitl Blanco-Cano, Lucile Turc, Primož Kajdič, Andreas Johlander, Vertti Tarvus, Stephen Fuselier, Karlheinz Trattner, Markku Alho, Thiago Brito, Urs Ganse, Yann Pfau-Kempf, Mojtaba Akhavan-Tafti, Tomas Karlsson, Savvas Raptis, Maxime Dubart, Maxime Grandin, Jonas Suni, and Minna Palmroth
Ann. Geophys., 38, 1081–1099, https://doi.org/10.5194/angeo-38-1081-2020, https://doi.org/10.5194/angeo-38-1081-2020, 2020
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We investigate the dynamics of helium in the foreshock, a part of near-Earth space found upstream of the Earth's bow shock. We show how the second most common ion in interplanetary space reacts strongly to plasma waves found in the foreshock. Spacecraft observations and supercomputer simulations both give us a new understanding of the foreshock edge and how to interpret future observations.
Markus Battarbee, Urs Ganse, Yann Pfau-Kempf, Lucile Turc, Thiago Brito, Maxime Grandin, Tuomas Koskela, and Minna Palmroth
Ann. Geophys., 38, 625–643, https://doi.org/10.5194/angeo-38-625-2020, https://doi.org/10.5194/angeo-38-625-2020, 2020
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The structure and medium-scale dynamics of Earth's bow shock and how charged solar wind particles are reflected by it are studied in order to better understand space weather effects. We use advanced supercomputer simulations to model the shock and reflected ions. We find that the thickness of the shock depends on solar wind conditions but also has small-scale variations. Charged particle reflection is shown to be non-localized. Magnetic fields are important for ion reflection.
Anatoli A. Petrukovich, Olga M. Chugunova, and Pavel I. Shustov
Ann. Geophys., 37, 877–889, https://doi.org/10.5194/angeo-37-877-2019, https://doi.org/10.5194/angeo-37-877-2019, 2019
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Earth's bow shock in solar wind with high thermal and low magnetic pressure is a rare phenomenon. However, such an object is ubiquitous in astrophysical plasmas.
We surveyed statistics of such shock observations since 1995. About 100 crossings were initially identified. In this report 22 crossings from the Cluster project were studied using multipoint analysis, which allowed for the determination of the spatial scales of the shock transition and of the dominant magnetic variations
Gábor Facskó
Ann. Geophys., 37, 763–764, https://doi.org/10.5194/angeo-37-763-2019, https://doi.org/10.5194/angeo-37-763-2019, 2019
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Blanco-Cano et al. (2018) intended to find a type of transient event in the solar wind before the terrestrial bow shock using a special type of simulation. However, the simulation results cannot reproduce the main features of the event. Based on the remarks described below, I am sure that the features in the simulations are not those types of events. The Vlasiator code simulated proto-SHFAs.
Christopher A. Gurgiolo, Melvyn L. Goldstein, and Adolfo Viñas
Ann. Geophys., 37, 243–261, https://doi.org/10.5194/angeo-37-243-2019, https://doi.org/10.5194/angeo-37-243-2019, 2019
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The reflection of solar wind electrons at the bow shock helps define the physical properties of the foreshock, the region where the interplanetary magnetic field directly connects to the bow shock. We report that the strahl, the field-aligned component of the electron solar wind distribution, appears to be nearly fully reflected at the bow shock and that the reflection occurs in the foot of the shock, implying that mirroring is not the primary cause of the electron reflection.
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Short summary
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.
We use the Vlasiator code to study the characteristics of transient structures that exist in the...
