Articles | Volume 39, issue 1
https://doi.org/10.5194/angeo-39-239-2021
© Author(s) 2021. 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-39-239-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Statistical study of linear magnetic hole structures near Earth
Space Research Institute, Austrian Academy of Sciences, Graz, Austria
David Mautner
Space Research Institute, Austrian Academy of Sciences, Graz, Austria
Cyril Simon Wedlund
Space Research Institute, Austrian Academy of Sciences, Graz, Austria
Charlotte Goetz
ESTEC, European Space Agency, Keplerlaan 1, 2201AZ Noordwijk, the Netherlands
Ferdinand Plaschke
Space Research Institute, Austrian Academy of Sciences, Graz, Austria
Tomas Karlsson
Department of Space and Plasma Physics, School of Electrical Engineering and Computer Science, Royal Institute of Technology, Stockholm, Sweden
Daniel Schmid
Space Research Institute, Austrian Academy of Sciences, Graz, Austria
Diana Rojas-Castillo
Space Research Institute, Austrian Academy of Sciences, Graz, Austria
Instituto de Geofísica, UNAM, Ciudad Universitaria, Coyoacán, CP 04510, Mexico City, Mexico
Owen W. Roberts
Space Research Institute, Austrian Academy of Sciences, Graz, Austria
Ali Varsani
Space Research Institute, Austrian Academy of Sciences, Graz, Austria
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Ariel Tello Fallau, Charlotte Goetz, Cyril Simon Wedlund, Martin Volwerk, and Anja Moeslinger
Ann. Geophys., 41, 569–587, https://doi.org/10.5194/angeo-41-569-2023, https://doi.org/10.5194/angeo-41-569-2023, 2023
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The plasma environment of comet 67P provides a unique laboratory to study plasma phenomena in the solar system. Previous studies have reported the existence of mirror modes at 67P but no further systematic investigation has so far been done. This study aims to learn more about these waves. We investigate the magnetic field measured by Rosetta and find 565 mirror mode signatures. The detected mirror modes are likely generated upstream of the observation and have been modified by the plasma.
Martin Volwerk, Cyril Simon Wedlund, David Mautner, Sebastián Rojas Mata, Gabriella Stenberg Wieser, Yoshifumi Futaana, Christian Mazelle, Diana Rojas-Castillo, César Bertucci, and Magda Delva
Ann. Geophys., 41, 389–408, https://doi.org/10.5194/angeo-41-389-2023, https://doi.org/10.5194/angeo-41-389-2023, 2023
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Ann. Geophys., 41, 225–251, https://doi.org/10.5194/angeo-41-225-2023, https://doi.org/10.5194/angeo-41-225-2023, 2023
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Mirror modes are magnetic bottles found in the space plasma environment of planets contributing to the energy exchange with the solar wind. We use magnetic field measurements from the NASA Mars Atmosphere and Volatile EvolutioN mission to detect them around Mars and show how they evolve in time and space. The structures concentrate in two regions: one behind the bow shock and the other closer to the planet. They compete with other wave modes depending on the solar flux and heliocentric distance.
Martin Volwerk, Beatriz Sánchez-Cano, Daniel Heyner, Sae Aizawa, Nicolas André, Ali Varsani, Johannes Mieth, Stefano Orsini, Wolfgang Baumjohann, David Fischer, Yoshifumi Futaana, Richard Harrison, Harald Jeszenszky, Iwai Kazumasa, Gunter Laky, Herbert Lichtenegger, Anna Milillo, Yoshizumi Miyoshi, Rumi Nakamura, Ferdinand Plaschke, Ingo Richter, Sebastián Rojas Mata, Yoshifumi Saito, Daniel Schmid, Daikou Shiota, and Cyril Simon Wedlund
Ann. Geophys., 39, 811–831, https://doi.org/10.5194/angeo-39-811-2021, https://doi.org/10.5194/angeo-39-811-2021, 2021
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On 15 October 2020, BepiColombo used Venus as a gravity assist to change its orbit to reach Mercury in late 2021. During this passage of Venus, the spacecraft entered into Venus's magnetotail at a distance of 70 Venus radii from the planet. We have studied the magnetic field and plasma data and find that Venus's magnetotail is highly active. This is caused by strong activity in the solar wind, where just before the flyby a coronal mass ejection interacted with the magnetophere of Venus.
Daniel Schmid, Yasuhito Narita, Ferdinand Plaschke, Martin Volwerk, Rumi Nakamura, and Wolfgang Baumjohann
Ann. Geophys., 39, 563–570, https://doi.org/10.5194/angeo-39-563-2021, https://doi.org/10.5194/angeo-39-563-2021, 2021
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In this work we present the first analytical magnetosheath plasma flow model for the space environment around Mercury. The proposed model is relatively simple to implement and provides the possibility to trace the flow lines inside the Hermean magnetosheath. It can help to determine the the local plasma conditions of a spacecraft in the magnetosheath exclusively on the basis of the upstream solar wind parameters.
Gerlinde Timmermann, David Fischer, Hans-Ulrich Auster, Ingo Richter, Benjamin Grison, and Ferdinand Plaschke
EGUsphere, https://doi.org/10.5194/egusphere-2025-4095, https://doi.org/10.5194/egusphere-2025-4095, 2025
This preprint is open for discussion and under review for Geoscientific Instrumentation, Methods and Data Systems (GI).
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We've compared the amplitude spectral densities of a fluxgate magnetometer (FGM) and an anisotropic magnetoresistive (AMR) magnetometer during ground testing with the amplitude spectral densities obtained in different regions of near-Earth space. The FGM can measure the fields in the different space regions and their fluctuations within a frequency range of 1 mHz to 2.5 Hz. The AMR magnetometer is only suitable for more turbulent regions such as the magnetosheath due to its higher noise levels.
Yasuhito Narita, Daniel Schmid, and Uwe Motschmann
Ann. Geophys., 43, 417–425, https://doi.org/10.5194/angeo-43-417-2025, https://doi.org/10.5194/angeo-43-417-2025, 2025
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It is often the case that only magnetic field data are available for in situ planetary studies using spacecraft. Either plasma data are not available or the data resolution is limited. Nevertheless, the theory of plasma instability tells us how to interpret the magnetic field data (wave frequency) in terms of flow speed and beam velocity, generating the instability. We invent an analysis tool for Mercury's upstream waves as an example.
Niklas Grimmich, Adrian Pöppelwerth, Martin Owain Archer, David Gary Sibeck, Ferdinand Plaschke, Wenli Mo, Vicki Toy-Edens, Drew Lawson Turner, Hyangpyo Kim, and Rumi Nakamura
Ann. Geophys., 43, 151–173, https://doi.org/10.5194/angeo-43-151-2025, https://doi.org/10.5194/angeo-43-151-2025, 2025
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The boundary of Earth's magnetic field, the magnetopause, deflects and reacts to the solar wind, the energetic particles emanating from the Sun. We find that certain types of solar wind favour the occurrence of deviations between the magnetopause locations observed by spacecraft and those predicted by models. In addition, the turbulent region in front of the magnetopause, the foreshock, has a large influence on the location of the magnetopause and thus on the accuracy of the model predictions.
Niklas Grimmich, Ferdinand Plaschke, Benjamin Grison, Fabio Prencipe, Christophe Philippe Escoubet, Martin Owain Archer, Ovidiu Dragos Constantinescu, Stein Haaland, Rumi Nakamura, David Gary Sibeck, Fabien Darrouzet, Mykhaylo Hayosh, and Romain Maggiolo
Ann. Geophys., 42, 371–394, https://doi.org/10.5194/angeo-42-371-2024, https://doi.org/10.5194/angeo-42-371-2024, 2024
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In our study, we looked at the boundary between the Earth's magnetic field and the interplanetary magnetic field emitted by the Sun, called the magnetopause. While other studies focus on the magnetopause motion near Earth's Equator, we have studied it in polar regions. The motion of the magnetopause is faster towards the Earth than towards the Sun. We also found that the occurrence of unusual magnetopause locations is due to similar solar influences in the equatorial and polar regions.
Adrian Pöppelwerth, Georg Glebe, Johannes Z. D. Mieth, Florian Koller, Tomas Karlsson, Zoltán Vörös, and Ferdinand Plaschke
Ann. Geophys., 42, 271–284, https://doi.org/10.5194/angeo-42-271-2024, https://doi.org/10.5194/angeo-42-271-2024, 2024
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In the magnetosheath, a near-Earth region of space, we observe increases in plasma velocity and density, so-called jets. As they propagate towards Earth, jets interact with the ambient plasma. We study this interaction with three spacecraft simultaneously to infer their sizes. While previous studies have investigated their size almost exclusively statistically, we demonstrate a new method of determining the sizes of individual jets.
Tomas Karlsson, Ferdinand Plaschke, Austin N. Glass, and Jim M. Raines
Ann. Geophys., 42, 117–130, https://doi.org/10.5194/angeo-42-117-2024, https://doi.org/10.5194/angeo-42-117-2024, 2024
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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 show for the first time that SLAMS also exist there.
Yasuhito Narita, Daniel Schmid, and Simon Toepfer
Ann. Geophys., 42, 79–89, https://doi.org/10.5194/angeo-42-79-2024, https://doi.org/10.5194/angeo-42-79-2024, 2024
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The magnetosheath is a transition layer surrounding the planetary magnetosphere. We develop an algorithm to compute the plasma flow velocity and magnetic field for a more general shape of magnetosheath using the concept of potential field and suitable coordinate transformation. Application to the empirical Earth magnetosheath region is shown in the paper. The developed algorithm is useful when interpreting the spacecraft data or simulation of the planetary magnetosheath region.
Ariel Tello Fallau, Charlotte Goetz, Cyril Simon Wedlund, Martin Volwerk, and Anja Moeslinger
Ann. Geophys., 41, 569–587, https://doi.org/10.5194/angeo-41-569-2023, https://doi.org/10.5194/angeo-41-569-2023, 2023
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The plasma environment of comet 67P provides a unique laboratory to study plasma phenomena in the solar system. Previous studies have reported the existence of mirror modes at 67P but no further systematic investigation has so far been done. This study aims to learn more about these waves. We investigate the magnetic field measured by Rosetta and find 565 mirror mode signatures. The detected mirror modes are likely generated upstream of the observation and have been modified by the plasma.
Leonard Schulz, Karl-Heinz Glassmeier, Ferdinand Plaschke, Simon Toepfer, and Uwe Motschmann
Ann. Geophys., 41, 449–463, https://doi.org/10.5194/angeo-41-449-2023, https://doi.org/10.5194/angeo-41-449-2023, 2023
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The upper detection limit in reciprocal space, the spatial Nyquist limit, is derived for arbitrary spatial dimensions for the wave telescope analysis technique. This is important as future space plasma missions will incorporate larger numbers of spacecraft (>4). Our findings are a key element in planning the spatial distribution of future multi-point spacecraft missions. The wave telescope is a multi-dimensional power spectrum estimator; hence, this can be applied to other fields of research.
Martin Volwerk, Cyril Simon Wedlund, David Mautner, Sebastián Rojas Mata, Gabriella Stenberg Wieser, Yoshifumi Futaana, Christian Mazelle, Diana Rojas-Castillo, César Bertucci, and Magda Delva
Ann. Geophys., 41, 389–408, https://doi.org/10.5194/angeo-41-389-2023, https://doi.org/10.5194/angeo-41-389-2023, 2023
Short summary
Short summary
Freshly created ions in solar wind start gyrating around the interplanetary magnetic field. When they cross the bow shock, they get an extra kick, and this increases the plasma pressure against the magnetic pressure. This leads to the creation of so-called mirror modes, regions where the magnetic field decreases in strength and the plasma density increases. These structures help in exploring how energy is transferred from the ions to the magnetic field and where around Venus this is happening.
Henriette Trollvik, Tomas Karlsson, and Savvas Raptis
Ann. Geophys., 41, 327–337, https://doi.org/10.5194/angeo-41-327-2023, https://doi.org/10.5194/angeo-41-327-2023, 2023
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The solar wind is in a plasma state and can exhibit a range of phenomena like waves and instabilities. One observed phenomenon in the solar wind is magnetic holes (MHs). They are localized depressions in the magnetic field. We studied the motion of MHs using the multispacecraft ESA Cluster mission. We derived their velocities in the solar wind frame and found that both linear and rotational MHs are convected with the solar wind.
Cyril Simon Wedlund, Martin Volwerk, Christian Mazelle, Sebastián Rojas Mata, Gabriella Stenberg Wieser, Yoshifumi Futaana, Jasper Halekas, Diana Rojas-Castillo, César Bertucci, and Jared Espley
Ann. Geophys., 41, 225–251, https://doi.org/10.5194/angeo-41-225-2023, https://doi.org/10.5194/angeo-41-225-2023, 2023
Short summary
Short summary
Mirror modes are magnetic bottles found in the space plasma environment of planets contributing to the energy exchange with the solar wind. We use magnetic field measurements from the NASA Mars Atmosphere and Volatile EvolutioN mission to detect them around Mars and show how they evolve in time and space. The structures concentrate in two regions: one behind the bow shock and the other closer to the planet. They compete with other wave modes depending on the solar flux and heliocentric distance.
Yasuhito Narita, Simon Toepfer, and Daniel Schmid
Ann. Geophys., 41, 87–91, https://doi.org/10.5194/angeo-41-87-2023, https://doi.org/10.5194/angeo-41-87-2023, 2023
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Magnetopause is a shielding boundary of planetary magnetic field. Many mathematical models have been proposed to describe or to reproduce the magnetopause location, but they are restricted to the real-number functions. In this work, we analytically develop a magnetopause model in the complex-number domain, which is advantageous in deforming the magnetopause shape in a conformal (angle-preserving) way, and is suited to compare different models or map one model onto another.
Daniel Schmid and Yasuhito Narita
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2022-30, https://doi.org/10.5194/angeo-2022-30, 2023
Revised manuscript not accepted
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Here we present a useful tool to diagnose the bow shock condition around planets on basis of magnetic field observations. From the upstream and downstream shock normal angle of the magnetic field, it is possible to approximate the relation between compression ratio, Alfvenic Mach number and the solar wind plasma beta. The tool is particularly helpful to study the solar wind conditions and bow shock characteristics during the planetary flybys of the ongoing BepiColombo mission.
Tomas Karlsson, Henriette Trollvik, Savvas Raptis, Hans Nilsson, and Hadi Madanian
Ann. Geophys., 40, 687–699, https://doi.org/10.5194/angeo-40-687-2022, https://doi.org/10.5194/angeo-40-687-2022, 2022
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Magnetic holes are curious localized dropouts of magnetic field strength in the solar wind (the flow of ionized gas continuously streaming out from the sun). In this paper we show that these magnetic holes can cross the bow shock (where the solar wind brake down to subsonic velocity) and enter the region close to Earth’s magnetosphere. These structures may therefore represent a new type of non-uniform solar wind–magnetosphere interaction.
Martin Volwerk, Beatriz Sánchez-Cano, Daniel Heyner, Sae Aizawa, Nicolas André, Ali Varsani, Johannes Mieth, Stefano Orsini, Wolfgang Baumjohann, David Fischer, Yoshifumi Futaana, Richard Harrison, Harald Jeszenszky, Iwai Kazumasa, Gunter Laky, Herbert Lichtenegger, Anna Milillo, Yoshizumi Miyoshi, Rumi Nakamura, Ferdinand Plaschke, Ingo Richter, Sebastián Rojas Mata, Yoshifumi Saito, Daniel Schmid, Daikou Shiota, and Cyril Simon Wedlund
Ann. Geophys., 39, 811–831, https://doi.org/10.5194/angeo-39-811-2021, https://doi.org/10.5194/angeo-39-811-2021, 2021
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On 15 October 2020, BepiColombo used Venus as a gravity assist to change its orbit to reach Mercury in late 2021. During this passage of Venus, the spacecraft entered into Venus's magnetotail at a distance of 70 Venus radii from the planet. We have studied the magnetic field and plasma data and find that Venus's magnetotail is highly active. This is caused by strong activity in the solar wind, where just before the flyby a coronal mass ejection interacted with the magnetophere of Venus.
Daniel Schmid, Yasuhito Narita, Ferdinand Plaschke, Martin Volwerk, Rumi Nakamura, and Wolfgang Baumjohann
Ann. Geophys., 39, 563–570, https://doi.org/10.5194/angeo-39-563-2021, https://doi.org/10.5194/angeo-39-563-2021, 2021
Short summary
Short summary
In this work we present the first analytical magnetosheath plasma flow model for the space environment around Mercury. The proposed model is relatively simple to implement and provides the possibility to trace the flow lines inside the Hermean magnetosheath. It can help to determine the the local plasma conditions of a spacecraft in the magnetosheath exclusively on the basis of the upstream solar wind parameters.
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
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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.
Yasuhito Narita, Ferdinand Plaschke, Werner Magnes, David Fischer, and Daniel Schmid
Geosci. Instrum. Method. Data Syst., 10, 13–24, https://doi.org/10.5194/gi-10-13-2021, https://doi.org/10.5194/gi-10-13-2021, 2021
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The systematic error of calibrated fluxgate magnetometer data is studied for a spinning spacecraft. The major error comes from the offset uncertainty when the ambient magnetic field is low, while the error represents the combination of non-orthogonality, misalignment to spacecraft reference direction, and gain when the ambient field is high. The results are useful in developing future high-precision magnetometers and an error estimate in scientific studies using magnetometer data.
Ovidiu Dragoş Constantinescu, Hans-Ulrich Auster, Magda Delva, Olaf Hillenmaier, Werner Magnes, and Ferdinand Plaschke
Geosci. Instrum. Method. Data Syst., 9, 451–469, https://doi.org/10.5194/gi-9-451-2020, https://doi.org/10.5194/gi-9-451-2020, 2020
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We propose a gradiometer-based technique for cleaning multi-sensor magnetic field data acquired on board spacecraft. The technique takes advantage on the fact that the maximum-variance direction of many AC disturbances on board spacecraft does not change over time. We apply the proposed technique to the SOSMAG instrument on board GeoKompsat-2A. We analyse the performance and limitations of the technique and discuss in detail how various disturbances are removed.
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.
Cited articles
Angelopoulos, V.: The ARTEMIS Mission, Space Sci. Rev., 165, 3–15,
https://doi.org/10.1007/s11214-010-9687-2, 2011. a
Artemyev, A. V., Algelopoulos, V., and McTiernan, J. M.: Near-Earth Solar
Wind: Plasma Characteristics From ARTEMIS Measurements, J. Geophys. Res.,
123, 9955–9962, https://doi.org/10.1029/2018JA025904, 2018. a
Bandyopadhyay, R., Matthaeus, W. H., C. T. Russell, A. C., Strangeway,
R. J., Torbert, R. B., Giles, B. L., Gershman, D. J., Pollock, C. J., and
Burch, J. L.: Direct Measurement of the Solar-wind Taylor Microscale Using MMS Turbulence Campaign Data, Astrophys. J., 899, 63,
https://doi.org/10.3847/1538-4357/ab9ebe, 2020. a, b
Bohm, D., Burhop, E. H. S., and Massey, H. S. W.: The use of probes for plasma exploration in strong magnetic fields, in: The characteristics of electrical discharges in magnetic fields, edited by: Guthrie, A. and Wakerling, R. K., McGraw-Hill, New York, 13–76, 1949. a
Burch, J. L., Moore, T. E., Torbert, R. B., and Giles, B. L.: Magnetospheric
Multiscale overview and science objectives, Space Sci. Rev., 199, 5–21,
https://doi.org/10.1007/s11214-015-0164-9, 2016. a
Burlaga, L., Scudder, J., Klein, L., and Isenberg, P.: Pressure-balanced
structures between 1 AU and 24 AU and their implications for solar wind
electrons and interstellar pickup ions, J. Geophys. Res., 95, 2229–2239,
https://doi.org/10.1029/JA095iA03p02229, 1990. a, b
Burlaga, L. F. and Lemaire, J. F.: Interplanetary Magnetic Holes: Theory, J.
Geophys. Res., 83, 5157–5160, https://doi.org/10.1029/JA083iA11p05157, 1978. a, b
Burlaga, L. F., Ness, N. F., and Acuna, M. H.: Linear magnetic holes in a
unipolar region of the heliosheath observed by Voyager 1, J. Geophys. Res.,
112, A07106, https://doi.org/10.1029/2007JA012292, 2007. a
Gary, S. P., Fuselier, S. A., and Anderson, B. J.: Ion anisotropy instabilities in the magnetosheath, J. Geophys. Res., 98, 1481–1488, 1993. a
Greenstadt, E. W., Green, I. M., Inouye, T. T., Hundhausen, A. J., Bame, S. J., and Strong, I. B.: Correlated magnetic field and plasma observations of the Earth's bow shock, J. Geophys. Res., 73, 51–60,
https://doi.org/10.1029/JA073i001p00051, 1968. a
Hasegawa, A. and Tsurutani, B. T.: Mirror mode expansion in planetary
magnetosheaths: Bohm-like diffusion, Phys. Rev. Lett., 107, 245005,
https://doi.org/10.1103/PhysRevLett.107.245005, 2011. a
Hellinger, P.: Comment on the linear mirror instability threshold, Phys.
Plasmas, 14, 082105, https://doi.org/10.1063/1.2768318, 2007. a
Heppner, J. P., Sugiura, M., Skillman, T. L., Ledley, B. G., and Campbell, M.:
OGO A Magnetic field observations, J. Geophys. Res., 72, 5417–5471,
https://doi.org/10.1029/JZ072i021p05417, 1968. a
Kajdič, P., Blanco-Cano, X., Omidi, N., Meziane, K., Russell, C. T., Sauvaud, J.-A., Dandouras, I., and Lavraud, B.: Statistical study of foreshock cavitons, Ann. Geophys., 31, 2163–2178, https://doi.org/10.5194/angeo-31-2163-2013, 2013. a
Karlsson, T., Heyner, D., Volwerk, M., morooka, M., Plaschke, F., Goetz, C.,
and Hadid, L.: Magnetic holes in the solar wind and magnetosheath near
Mercury, J. Geophys. Res., submitted, 2020. a
King, J. H. and Papitashvili, N. E.: Solar wind spatial scales in and
comparisons of hourly Wind and ACE plasma and magnetic field data, J.
Geophys. Res., 110, A02104, https://doi.org/10.1029/2004JA010649, 2005. a
Klein, L. and Burlaga, L.: Interplanetary sector boundaries 1971–1973, J.
Geophys. Res., 85, 2269–2276, https://doi.org/10.1029/JA085iA05p02269, 1980. a
Leinweber, H. K., Bromund, K. R., Strangeway, R. J., and Magnes, W.: The MMS Fluxgate Magnetometers Science Data Products Guide, MMS Science Data Center, available at: https://lasp.colorado.edu/mms/sdc/public/search/ (last access: 22 February 2021), 2016. a
Lin, R. P., Anderson, K. A., Ashford, S., Carlson, C., Curtis, D., Ergun, R.,
McFadden, D. L. J., McCarthy, M., Parks, G. K., Rème, H., Bosqued, J. M.,
Coutelier, J., Cotin, F., D'Uston, C., Wenzel, K.-P., Sanderson, T. R.,
Henrion, J., Ronnet, J. C., and Paschmann, G.: A Three-Dimensional Plasma and Energetic Particle Investigation for the Wind Spacecraft, Space Sci. Rev., 71, 125–153, 1995. a
Madanian, H., Halekas, J. S., Mazelle, C. X., Omidi, N., Espley, J. R.,
Mitchell, D. L., and McFadden, J. P.: Magnetic holes upstream of the
Martian bow shock: MAVEN observations, J. Geophys. Res., 125,
e2019JA027198, https://doi.org/10.1029/2019JA027198, 2020. a, b, c
Meziane, K., Alrefay, T. Y., and Hamza, A. M.: On the shape and motion of the
Earth's bow shock, Planet. Space Sci., 93, 1–9,
https://doi.org/10.1016/j.pss.2014.01.006, 2014. a, b
Parks, G. K., Lee, E., Mozer, F., Wilber, M., Lucek, E., Dandouras, I.,
Rème, H., Mazelle, C., Cao, J. B., Meziane, K., Goldstein, M. L., and
Escoubet, P.: Larmor radius size density holes discovered in the solar wind
upstream of Earth's bow shock, Phys. Plasma, 13, 050701,
https://doi.org/10.1063/1.2201056, 2006. a
Plaschke, F., Karlsson, T., Götz, C., Möstl, C., Richter, I., Volwerk, M., Eriksson, A., Behar, E., and Goldstein, R.: First observations of magnetic holes deep within the coma of a comet, Astron. Astrophys., 618,
A114, https://doi.org/10.1051/0004-6361/201833300, 2018. a, b
Pollock, C., Moore, T., Jacques, A., Burch, J., Gliese, U., Saito, Y., Omoto,
T., Avanov, L., Barrie, A., Coffey, V., Dorelli, J., Gershman, D., Giles, B.,
rosnack, T., Salo, C., Yokota, S., Adrian, M., Aoustin, C., Auletti, C.,
Aung, S., Bigio, B., Cao, N., Chandler, M., Chornay, D., Christian, K.,
Clark, G., Collinson, G., Corris, T., De Los Santos, S., Devlin, R., Diaz,
T., Dickerson, T., Dickson, C., Diekmann, A., Diggs, F., Duncan, C.,
Figueroa-Vinas, S., Firman, C., Freeman, M., Galassi, N., Garcia, K.,
Goodhart, G., Guererro, D., Hageman, J., Hanley, J., Hemminger, E., Holland,
M., Hutchins, M., James, T., Jones, W., Kreisler, S., Kujawski, J., Lavu, V.,
Lobell, J., LeCompte, E., Lukemire, A., MacDonald, E., Mairano, A.,
Mukai, T., Narayanan, K., Nguyan, Q., Onizuka, M., Paterson, W., Persyn, S.,
Piepgrass, B., Cheney, F., Rager, A., Raghuram, T., Ramil, A., Reichenthal,
L., Rodriguez, H., Rouzaud, J., Rucker, A., Saito, Y., Samara, M., Sauvaud,
J.-A., Sschuster, D., Shappirio, M., Shelton, K., Sher, D., Smith, D., Smith,
K., Steinfeld, D., Szymkiewicz, R., Tanimoto, K., Taylor, J., Tucker, C.,
Tull, K., Uhl, A., Vloet, J., Walpole, P., Weidner, S., White, D., Winkert,
G., Yeh, P.-S., and Zeuch, M.: Fast Plasma Investigation for Magnetospheric
Multiscale, Space Sci. Rev., 199, 331–406,
https://doi.org/10.1007/s11214-016-0245-4, 2016. a
Russell, C. T., Anderson, B. J., Baumjohann, W., Bromund, K. R., Dearborn, D., Fischer, D., Le, G., Leinweber, H. K., Leneman, D., Magnes, W., Means, J. D., Moldwin, M. B., Nakamura, R., Pierce, D., Plaschke, F., Rowe, K. M., Slavin, J. A., Strangeway, R. J., Torbert, R., Hagen, C., Jernej, I., Valavanoglou, A., and Richter, I.: The magnetospheric multiscale magnetometers, Space Sci. Rev., 199, 189–256, https://doi.org/10.1007/s11214-014-0057-3, 2016. a
Scarf, F. L., Fredricks, R. W., Frank, L. A., Russell, C. T., Coleman Jr.,
P. J., and Neugebauer, M.: Direct correlations of large-amplitude waves with
suprathermal protons in the upstream solar wind, J. Geophys. Res., 75, 7316–7322, https://doi.org/10.1029/JA075i034p07316, 1970. a
Schmid, D., Volwerk, M., Plaschke, F., Vörös, Z., Zhang, T. L., Baumjohann, W., and Narita, Y.: Mirror mode structures near Venus and Comet P/Halley, Ann. Geophys., 32, 651–657, https://doi.org/10.5194/angeo-32-651-2014, 2014. a
Schwartz, S., Avanov, L., Turner, D., Zhang, H., Gingell, I., Eastwood, J.,
Gershman, D., Johlander, A., Russell, C., Burch, J., Dorelli, J., Erkisson,
S., Ergun, R., Fuselier, S., Giles, B., Goodrich, K., Khotyaintsev, Z.,
Lauvraud, B., Lindqvist, P.-A., Oka, M., Phan, T.-D., Strangeway, R.,
Trattner, K., Torbert, R., Vaivads, A., Wei, H., and Wilder, F.: Ion kinetics in a hot flow anomaly: MMS observations, Geophys. Res. Lett., 45, 11520–11529, https://doi.org/10.1029/2018GL080189, 2018. a
Schwartz, S. J.: Hot flow anomalies near the Earth's bow shock, Adv. Space
Sci., 15, 107–116, https://doi.org/10.1016/0273-1177(94)00092-F, 1995. a
Schwartz, S. J.: Schock and discontinuity normals, Mach numbers, and related parameters, in: Analysis Methods for Multi-Spacecraft Data, edited by: Paschmann, G. and Daly, P., ESA, Noordwijk, 249–270, 1998. a
Sergeev, V. A., Sormakov, D. A., Apatenkov, S. V., Baumjohann, W., Nakamura, R., Runov, A. V., Mukai, T., and Nagai, T.: Survey of large-amplitude flapping motions in the midtail current sheet, Ann. Geophys., 24, 2015–2024, https://doi.org/10.5194/angeo-24-2015-2006, 2006. a
Sibeck, D. B., Phan, T.-D., Lin, R., Lepping, R. P., and Szabo, A.: Wind
observations of foreshock cavities: A case study, J. Geophys. Res., 107,
1271, https://doi.org/10.1029/2001JA007539, 2002. a
Sibeck, D. G., Kudela, K., Mukai, T., Nemecek, Z., and Safrankova, J.: Radial dependence of foreshock cavities: a case study, Ann. Geophys., 22, 4143–4151, https://doi.org/10.5194/angeo-22-4143-2004, 2004. a
Sonnerup, B. U. Ö. and Scheible, M.: Minimum and maximum variance analysis, in: Analysis Methods for Multi-Spacecraft Data, edited by: Paschmann, G. and Daly, P., ESA, Noordwijk, 185–220, 1998. a
Southwood, D. J. and Kivelson, M. G.: Mirror instability: 1. Physical mechanism of linear instability, J. Geophys. Res., 98, 9181–9187, 1993. a
Stevens, M. L. and Kasper, J. C.: A scale-free analysis of magnetic holes at 1 AU, J. Geophys. Res., 112, A05109, https://doi.org/10.1029/2006JA012116, 2007. a, b, c, d
Turner, D. L., Liu, T. Z., Wilson III, L. B., Cohen, I. J., Gershman, D. G., Fennell, J. F., Blake, J. B., Mauk, B. H., Omidi, N., and Burch, J. L.: Microscopic, Multipoint Characterization of Foreshock Bubbles With
Magnetospheric Multiscale (MMS), J. Geophys. Res., 125, e2019JA027707,
https://doi.org/10.1029/2019JA027707, 2020.
a
Wang, G. Q., Volwerk, M., Wu, M. Y., f. Hao, Y., Xiao, S. D., Wang, G., Liu,
L. J., Chen, Y. Q., and Zhang, T. L.: First observations of an ion vortex in a magnetic hole in the solar wind by MMS, Astrophys. J., submitted, 2020a. a
Wang, G. Q., Zhang, T. L., Wu, M. Y., Hao, Y. F., Xiao, S. D., Wang, G.,
Liu, L. J., Chen, Y. Q., and Volwerk, M.: Study of the Electron Velocity
Inside Sub-Ion-Scale Magnetic Holes in the Solar Wind by MMS Observations, J. Geophys. Res., 125, e2020JA028386, https://doi.org/10.1029/2020JA028386,
2020b. a, b
Wang, G. Q., Zhang, T. L., Xiao, S. D., Wu, M. Y., Wang, G., Liu, L. J., Chen,
Y. Q., and Volwerk, M.: Statistical Properties of Sub-Ion Magnetic Holes in
the Solar Wind at 1 AU, J. Geophys. Res., 125, e2020JA028320,
https://doi.org/10.1029/2020JA028320, 2020c. a
Winterhalter, D., Neugebauer, M., Goldstein, B. E., Smith, E. J., Bame, S. J.,
and Balogh, A.: Ulysses field and plasma observations of magnetic holes in
the solar wind and their relation to mirror-mode structures, J. Geophys.
Res., 99, 23371–23382, https://doi.org/10.1029/94JA01977, 1994. a
Winterhalter, D., Neugebauer, M., Goldstein, B. E., Smith, E. J., Tsurutani,
B. T., Bame, S. J., and Balogh, A.: Magnetic holes in the solar wind and
their relation to mirror-mode structures, Space Sci. Rev., 72, 201–204,
https://doi.org/10.1007/BF00768780, 1995. a, b, c
Winterhalter, D., Smith, E. J., Neugebauer, M., Goldstein, B. E., and
Tsurutani, B. T.: The latitudinal distribution of solar wind magnetic holes, Geophys. Res. Lett., 27, 1615–1618, https://doi.org/10.1029/1999GL003717, 2000. a, b
Xiao, T., Shi, Q. Q., Tian, A. M., Sun, W. J., Zhang, H., Shen, X. C., Shang,
W. S., and Du, A. M.: Plasma and Magnetic-Field Characteristics of Magnetic
Decreases in the Solar Wind at 1 AU: Cluster-C1 Observations, Sol. Phys.,
289, 3175–3195, https://doi.org/10.1007/s11207-014-0521-y, 2014. a, b, c, d, e
Zhang, T. L., Russell, C. T., Baumjohann, W., Jian, L. K., Balikhin, M. A.,
Cao, J. B., Wang, C., Blanco-Cano, X., Glassmeier, K.-H., Zambelli, W.,
Volwerk, M., Delva, M., and Vörös, Z.: Characteristic size and shape of
the mirror mode structures in the solar wind at 0.72 AU, Geophys. Res.
Lett., 35, L10106, https://doi.org/10.1029/2008GL033793, 2008. a, b
Zhao, L. L., Zhang, H., and Zong, Q.-G.: A statistical study on hot flow anomaly current sheets, J. Geophys. Res., 122, 235–248,
https://doi.org/10.1002/2016JA023319, 2017. a
Short summary
The magnetic field in the solar wind is not constant but varies in direction and strength. One of these variations shows a strong local reduction of the magnetic field strength and is called a magnetic hole. These holes are usually an indication that there is, or has been, a temperature difference in the plasma of the solar wind, with the temperature along the magnetic field lower than perpendicular. The MMS spacecraft data have been used to study the characteristics of these holes near Earth.
The magnetic field in the solar wind is not constant but varies in direction and strength. One...