Articles | Volume 34, issue 9
https://doi.org/10.5194/angeo-34-759-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/angeo-34-759-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Regular paper
| 
16 Sep 2016
Regular paper |
| 16 Sep 2016
On determining fluxgate magnetometer spin axis offsets from mirror mode observations
Ferdinand Plaschke
CORRESPONDING AUTHOR
Space Research Institute, Austrian Academy of Sciences, Schmiedlstrasse 6, 8042 Graz, Austria
Yasuhito Narita
Space Research Institute, Austrian Academy of Sciences, Schmiedlstrasse 6, 8042 Graz, Austria
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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
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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.
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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.
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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.
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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.
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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, 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
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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.
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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.
Martin Volwerk, David Mautner, Cyril Simon Wedlund, Charlotte Goetz, Ferdinand Plaschke, Tomas Karlsson, Daniel Schmid, Diana Rojas-Castillo, Owen W. Roberts, and Ali Varsani
Ann. Geophys., 39, 239–253, https://doi.org/10.5194/angeo-39-239-2021, https://doi.org/10.5194/angeo-39-239-2021, 2021
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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.
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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.
Daniel Schmid, Ferdinand Plaschke, Yasuhito Narita, Daniel Heyner, Johannes Z. D. Mieth, Brian J. Anderson, Martin Volwerk, Ayako Matsuoka, and Wolfgang Baumjohann
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Recently, the two-spacecraft mission BepiColombo was launched to explore Mercury. To measure the magnetic field precisely, in-flight calibration of the magnetometer offset is needed. Usually, the offset is evaluated from magnetic field observations in the solar wind. Since one of the spacecraft will remain within Mercury's magnetic environment, we examine an alternative calibration method. We show that this method is applicable and may be a valuable tool to determine the offset accurately.
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Jets of solar-wind plasma commonly hit the Earth's magnetosphere. Using data from the four Magnetospheric Multiscale (MMS) spacecraft, we show statistically that within jets the magnetic field is more aligned with the plasma flow direction than outside of these jets. Our study confirms prior simulation results, but it also shows that the average effect is moderate. The jets' magnetic field is important with respect to their impact on space weather.
Martin Volwerk, Charlotte Goetz, Ferdinand Plaschke, Tomas Karlsson, Daniel Heyner, and Brian Anderson
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The magnetic field that is carried by the solar wind slowly decreases in strength as it moves further from the Sun. However, there are sometimes localized decreases in the magnetic field strength, called magnetic holes. These are small structures where the magnetic field strength decreases to less than 50 % of the surroundings and the plasma density increases. This paper presents a statistical study of the behaviour of these holes between Mercury and Venus using MESSENGER data.
Ferdinand Plaschke
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Measuring the magnetic field onboard spacecraft requires regular in-flight calibration activities. Among those, determining the output of magnetometers under vanishing ambient magnetic fields, the so-called magnetometer offsets, is essential. Typically, characteristic rotations in solar wind magnetic fields are used to obtain these offsets. This paper addresses the question of how many solar wind data are needed to reach certain accuracy levels in offset determination.
Laura Vuorinen, Heli Hietala, and Ferdinand Plaschke
Ann. Geophys., 37, 689–697, https://doi.org/10.5194/angeo-37-689-2019, https://doi.org/10.5194/angeo-37-689-2019, 2019
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Before the solar wind encounters the Earth's magnetic field, it is first slowed down and deflected by the Earth's bow shock. We find that downstream of the bow shock regions where the shock normal and the solar wind magnetic field are almost parallel and the shock is more rippled, plasma jets with high earthward velocities are observed significantly more often than elsewhere downstream of the shock. Our results help us forecast the occurrence of these jets and their effects on Earth.
Ferdinand Plaschke, Hans-Ulrich Auster, David Fischer, Karl-Heinz Fornaçon, Werner Magnes, Ingo Richter, Dragos Constantinescu, and Yasuhito Narita
Geosci. Instrum. Method. Data Syst., 8, 63–76, https://doi.org/10.5194/gi-8-63-2019, https://doi.org/10.5194/gi-8-63-2019, 2019
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Raw output of spacecraft magnetometers has to be converted into meaningful units and coordinate systems before it is usable for scientific applications. This conversion is defined by 12 calibration parameters, 8 of which are more easily determined in flight if the spacecraft is spinning. We present theory and advanced algorithms to determine these eight parameters. They take into account the physical magnetometer and spacecraft behavior, making them superior to previously published algorithms.
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.
Ferdinand Plaschke and Heli Hietala
Ann. Geophys., 36, 695–703, https://doi.org/10.5194/angeo-36-695-2018, https://doi.org/10.5194/angeo-36-695-2018, 2018
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Fast jets of solar wind particles drive through a slower environment in the magnetosheath, located sunward of the region dominated by the Earth’s magnetic field. THEMIS multi-spacecraft observations show that jets push ambient particles out of their way. These particles flow around the faster jets into the jets’ wake. Thereby, jets stir the magnetosheath, changing the properties of this key region whose particles and magnetic fields can directly interact with the Earth’s magnetic field.
Tomas Karlsson, Ferdinand Plaschke, Heli Hietala, Martin Archer, Xóchitl Blanco-Cano, Primož Kajdič, Per-Arne Lindqvist, Göran Marklund, and Daniel J. Gershman
Ann. Geophys., 36, 655–677, https://doi.org/10.5194/angeo-36-655-2018, https://doi.org/10.5194/angeo-36-655-2018, 2018
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We have studied fast plasma jets outside of Earth’s magnetic environment. Such jets are small-scale structures with a limited lifetime, which may be important in determining the properties of the near-Earth space environment, due to their concentrated kinetic energy. We have used data from the NASA Magnetospheric MultiScale (MMS) satellites to study their properties in detail, to understand how these jets are formed. We have found evidence that there are at least two different types of jets.
Sudong Xiao, Tielong Zhang, Guoqiang Wang, Martin Volwerk, Yasong Ge, Daniel Schmid, Rumi Nakamura, Wolfgang Baumjohann, and Ferdinand Plaschke
Ann. Geophys., 35, 1015–1022, https://doi.org/10.5194/angeo-35-1015-2017, https://doi.org/10.5194/angeo-35-1015-2017, 2017
Dennis Frühauff, Ferdinand Plaschke, and Karl-Heinz Glassmeier
Ann. Geophys., 35, 117–121, https://doi.org/10.5194/angeo-35-117-2017, https://doi.org/10.5194/angeo-35-117-2017, 2017
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Vector magnetic field instruments mounted on spacecraft require precise in-flight calibration of the offsets of all three axes, i.e., the output in vanishing ambient field. While calibration of the spin plane offsets is trivial, we apply a new technique for determining the spin axis offset, not relying on solar wind data but on magnetosheath encounters. This technique is successfully applied to the satellites of the THEMIS mission to update the calibration parameters of the complete mission.
Martin Volwerk, Daniel Schmid, Bruce T. Tsurutani, Magda Delva, Ferdinand Plaschke, Yasuhito Narita, Tielong Zhang, and Karl-Heinz Glassmeier
Ann. Geophys., 34, 1099–1108, https://doi.org/10.5194/angeo-34-1099-2016, https://doi.org/10.5194/angeo-34-1099-2016, 2016
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The behaviour of mirror mode waves in Venus's magnetosheath is investigated for solar minimum and maximum conditions. It is shown that the total observational rate of these waves does not change much; however, the distribution over the magnetosheath is significantly different, as well as the growth and decay of the waves during these different solar activity conditions.
David Fischer, Werner Magnes, Christian Hagen, Ivan Dors, Mark W. Chutter, Jerry Needell, Roy B. Torbert, Olivier Le Contel, Robert J. Strangeway, Gernot Kubin, Aris Valavanoglou, Ferdinand Plaschke, Rumi Nakamura, Laurent Mirioni, Christopher T. Russell, Hannes K. Leinweber, Kenneth R. Bromund, Guan Le, Lawrence Kepko, Brian J. Anderson, James A. Slavin, and Wolfgang Baumjohann
Geosci. Instrum. Method. Data Syst., 5, 521–530, https://doi.org/10.5194/gi-5-521-2016, https://doi.org/10.5194/gi-5-521-2016, 2016
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This paper describes frequency and timing calibration, modeling and data processing and calibration for MMS magnetometers, resulting in a merged search choil and fluxgate data product.
D. Schmid, M. Volwerk, F. Plaschke, Z. Vörös, T. L. Zhang, W. Baumjohann, and Y. Narita
Ann. Geophys., 32, 651–657, https://doi.org/10.5194/angeo-32-651-2014, https://doi.org/10.5194/angeo-32-651-2014, 2014
R. Nakamura, F. Plaschke, R. Teubenbacher, L. Giner, W. Baumjohann, W. Magnes, M. Steller, R. B. Torbert, H. Vaith, M. Chutter, K.-H. Fornaçon, K.-H. Glassmeier, and C. Carr
Geosci. Instrum. Method. Data Syst., 3, 1–11, https://doi.org/10.5194/gi-3-1-2014, https://doi.org/10.5194/gi-3-1-2014, 2014
F. Plaschke, H. Hietala, and V. Angelopoulos
Ann. Geophys., 31, 1877–1889, https://doi.org/10.5194/angeo-31-1877-2013, https://doi.org/10.5194/angeo-31-1877-2013, 2013
C. Nabert, K.-H. Glassmeier, and F. Plaschke
Ann. Geophys., 31, 419–437, https://doi.org/10.5194/angeo-31-419-2013, https://doi.org/10.5194/angeo-31-419-2013, 2013
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
EGUsphere, https://doi.org/10.5194/egusphere-2024-2956, https://doi.org/10.5194/egusphere-2024-2956, 2024
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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.
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
Short summary
Short summary
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.
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
Short summary
Short summary
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
Short summary
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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.
Simon Toepfer, Ida Oertel, Vanita Schiron, Yasuhito Narita, Karl-Heinz Glassmeier, Daniel Heyner, Patrick Kolhey, and Uwe Motschmann
Ann. Geophys., 40, 91–105, https://doi.org/10.5194/angeo-40-91-2022, https://doi.org/10.5194/angeo-40-91-2022, 2022
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Revealing the nature of Mercury’s internal magnetic field is one of the primary goals of the BepiColombo mission. Besides the parametrization of the magnetic field contributions, the application of a robust inversion method is of major importance. The present work provides an overview of the most commonly used inversion methods and shows that Capon’s method as well as the Tikhonov regularization enable a high-precision determination of Mercury’s internal magnetic field up to the fifth degree.
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
Short summary
Short summary
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.
Yasuhito Narita
Ann. Geophys., 39, 759–768, https://doi.org/10.5194/angeo-39-759-2021, https://doi.org/10.5194/angeo-39-759-2021, 2021
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Short summary
The concept of electromotive force appears in various electromagnetic applications in geophysical and astrophysical fluid studies. The electromotive force is being recognized as a useful tool to construct a more complete picture of turbulent space plasma and has the potential to test for the fundamental processes of dynamo mechanism in space.
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.
Martin Volwerk, David Mautner, Cyril Simon Wedlund, Charlotte Goetz, Ferdinand Plaschke, Tomas Karlsson, Daniel Schmid, Diana Rojas-Castillo, Owen W. Roberts, and Ali Varsani
Ann. Geophys., 39, 239–253, https://doi.org/10.5194/angeo-39-239-2021, https://doi.org/10.5194/angeo-39-239-2021, 2021
Short summary
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.
Horia Comişel, Yasuhito Narita, and Uwe Motschmann
Ann. Geophys., 39, 165–170, https://doi.org/10.5194/angeo-39-165-2021, https://doi.org/10.5194/angeo-39-165-2021, 2021
Short summary
Short summary
Identification of a large-amplitude Alfvén wave decaying into a pair of
ion-acoustic and daughter Alfvén waves is one of the major goals in the
observational studies of space plasma nonlinearity.
Growth-rate maps
may serve as a useful tool for predictions of the wavevector spectrum of density
or magnetic field fluctuations in various scenarios for the
wave–wave coupling processes developing at different stages in
space plasma turbulence.
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
Short summary
Short summary
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.
Simon Toepfer, Yasuhito Narita, Daniel Heyner, Patrick Kolhey, and Uwe Motschmann
Geosci. Instrum. Method. Data Syst., 9, 471–481, https://doi.org/10.5194/gi-9-471-2020, https://doi.org/10.5194/gi-9-471-2020, 2020
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The Capon method serves as a powerful and robust data analysis tool when working on various kinds of ill-posed inverse problems. Besides the analysis of waves, the method can be used in a generalized way to compare actual measurements with theoretical models, such as Mercury's magnetic field analysis. In view to the BepiColombo mission this work establishes a mathematical basis for the application of Capon's method to analyze Mercury's internal magnetic field in a robust and manageable way.
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.
Daniel Schmid, Ferdinand Plaschke, Yasuhito Narita, Daniel Heyner, Johannes Z. D. Mieth, Brian J. Anderson, Martin Volwerk, Ayako Matsuoka, and Wolfgang Baumjohann
Ann. Geophys., 38, 823–832, https://doi.org/10.5194/angeo-38-823-2020, https://doi.org/10.5194/angeo-38-823-2020, 2020
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Recently, the two-spacecraft mission BepiColombo was launched to explore Mercury. To measure the magnetic field precisely, in-flight calibration of the magnetometer offset is needed. Usually, the offset is evaluated from magnetic field observations in the solar wind. Since one of the spacecraft will remain within Mercury's magnetic environment, we examine an alternative calibration method. We show that this method is applicable and may be a valuable tool to determine the offset accurately.
Ferdinand Plaschke, Maria Jernej, Heli Hietala, and Laura Vuorinen
Ann. Geophys., 38, 287–296, https://doi.org/10.5194/angeo-38-287-2020, https://doi.org/10.5194/angeo-38-287-2020, 2020
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Jets of solar-wind plasma commonly hit the Earth's magnetosphere. Using data from the four Magnetospheric Multiscale (MMS) spacecraft, we show statistically that within jets the magnetic field is more aligned with the plasma flow direction than outside of these jets. Our study confirms prior simulation results, but it also shows that the average effect is moderate. The jets' magnetic field is important with respect to their impact on space weather.
Martin Volwerk, Charlotte Goetz, Ferdinand Plaschke, Tomas Karlsson, Daniel Heyner, and Brian Anderson
Ann. Geophys., 38, 51–60, https://doi.org/10.5194/angeo-38-51-2020, https://doi.org/10.5194/angeo-38-51-2020, 2020
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The magnetic field that is carried by the solar wind slowly decreases in strength as it moves further from the Sun. However, there are sometimes localized decreases in the magnetic field strength, called magnetic holes. These are small structures where the magnetic field strength decreases to less than 50 % of the surroundings and the plasma density increases. This paper presents a statistical study of the behaviour of these holes between Mercury and Venus using MESSENGER data.
Ferdinand Plaschke
Geosci. Instrum. Method. Data Syst., 8, 285–291, https://doi.org/10.5194/gi-8-285-2019, https://doi.org/10.5194/gi-8-285-2019, 2019
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Measuring the magnetic field onboard spacecraft requires regular in-flight calibration activities. Among those, determining the output of magnetometers under vanishing ambient magnetic fields, the so-called magnetometer offsets, is essential. Typically, characteristic rotations in solar wind magnetic fields are used to obtain these offsets. This paper addresses the question of how many solar wind data are needed to reach certain accuracy levels in offset determination.
Horia Comişel, Yasuhito Narita, and Uwe Motschmann
Ann. Geophys., 37, 835–842, https://doi.org/10.5194/angeo-37-835-2019, https://doi.org/10.5194/angeo-37-835-2019, 2019
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Here we present a scenario that the decay of a field-aligned Alfvén wave can occur simultaneously at various angles to the mean magnetic field, generating a number of second-order fluctuations or waves (after the pump wave as the first-order fluctuation). We refer to the simultaneous decay as
multi-channel couplingsfollowing the notion in scattering theory. Our goal is to study the hypothesis of the multi-channel coupling by running a three-dimensional hybrid plasma simulation.
Yasuhito Narita, Wolfgang Baumjohann, and Rudolf A. Treumann
Ann. Geophys., 37, 825–834, https://doi.org/10.5194/angeo-37-825-2019, https://doi.org/10.5194/angeo-37-825-2019, 2019
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Scaling laws and energy spectra for the electric field, magnetic field, flow velocity, and density are theoretically derived for small-scale turbulence in space plasma on which the electrons behave as a fluid but the ions more as individual particles due to the difference in the mass (the Hall effect). Our theoretical model offers an explanation for the small-scale turbulence spectra measured in near-Earth space.
Laura Vuorinen, Heli Hietala, and Ferdinand Plaschke
Ann. Geophys., 37, 689–697, https://doi.org/10.5194/angeo-37-689-2019, https://doi.org/10.5194/angeo-37-689-2019, 2019
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Before the solar wind encounters the Earth's magnetic field, it is first slowed down and deflected by the Earth's bow shock. We find that downstream of the bow shock regions where the shock normal and the solar wind magnetic field are almost parallel and the shock is more rippled, plasma jets with high earthward velocities are observed significantly more often than elsewhere downstream of the shock. Our results help us forecast the occurrence of these jets and their effects on Earth.
Christoph Lhotka and Yasuhito Narita
Ann. Geophys., 37, 299–314, https://doi.org/10.5194/angeo-37-299-2019, https://doi.org/10.5194/angeo-37-299-2019, 2019
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The interplanetary magnetic field is a consequence of the solar magnetic field and the solar wind. Different magnetic field models exist in literature that allow us to better understand how the solar field extends throughout the solar system. We highlight different aspects of these different interplanetary magnetic field models and discuss possible applications. Verification of these models will become possible using data from the Parker Solar Probe and BepiColombo space mission.
Rudolf A. Treumann, Wolfgang Baumjohann, and Yasuhito Narita
Ann. Geophys., 37, 183–199, https://doi.org/10.5194/angeo-37-183-2019, https://doi.org/10.5194/angeo-37-183-2019, 2019
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Occasional deviations in density and magnetic power spectral densities in an intermediate frequency range are interpreted as an ion-inertial-range response to either the Kolmogorov or Iroshnikov–Kraichnan inertial-range turbulent velocity spectrum.
Ferdinand Plaschke, Hans-Ulrich Auster, David Fischer, Karl-Heinz Fornaçon, Werner Magnes, Ingo Richter, Dragos Constantinescu, and Yasuhito Narita
Geosci. Instrum. Method. Data Syst., 8, 63–76, https://doi.org/10.5194/gi-8-63-2019, https://doi.org/10.5194/gi-8-63-2019, 2019
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Raw output of spacecraft magnetometers has to be converted into meaningful units and coordinate systems before it is usable for scientific applications. This conversion is defined by 12 calibration parameters, 8 of which are more easily determined in flight if the spacecraft is spinning. We present theory and advanced algorithms to determine these eight parameters. They take into account the physical magnetometer and spacecraft behavior, making them superior to previously published algorithms.
Horia Comişel, Yasuhiro Nariyuki, Yasuhito Narita, and Uwe Motschmann
Ann. Geophys., 36, 1647–1655, https://doi.org/10.5194/angeo-36-1647-2018, https://doi.org/10.5194/angeo-36-1647-2018, 2018
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Space plasmas are assumed to be highly active and dynamic systems including waves and turbulence. Electromagnetic waves such as Alfven waves interact with one another, producing daughter waves. In our study based on three-dimensional hybrid simulations, we emphasize the role of obliquely propagating daughter waves in particle heating in low-temperature (or low-beta) plasmas. The evolutions of plasma turbulence, wave dissipation, and heating are essential problems in astrophysics.
Yasuhito Narita and Uwe Motschmann
Ann. Geophys., 36, 1537–1543, https://doi.org/10.5194/angeo-36-1537-2018, https://doi.org/10.5194/angeo-36-1537-2018, 2018
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Venus has no intrinsic magnetic field. On the other hand, we discover that an interplanetary magnetic field may nevertheless penetrate the planetary ionosphere by the diffusion process and reach the planetary surface when the solar wind condition remains for a sufficiently long time, between 12 and 54 h, depending on the condition of ionosphere.
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.
Gurbax S. Lakhina, Bruce T. Tsurutani, George J. Morales, Annick Pouquet, Masahiro Hoshino, Juan Alejandro Valdivia, Yasuhito Narita, and Roger Grimshaw
Nonlin. Processes Geophys., 25, 477–479, https://doi.org/10.5194/npg-25-477-2018, https://doi.org/10.5194/npg-25-477-2018, 2018
Ferdinand Plaschke and Heli Hietala
Ann. Geophys., 36, 695–703, https://doi.org/10.5194/angeo-36-695-2018, https://doi.org/10.5194/angeo-36-695-2018, 2018
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Fast jets of solar wind particles drive through a slower environment in the magnetosheath, located sunward of the region dominated by the Earth’s magnetic field. THEMIS multi-spacecraft observations show that jets push ambient particles out of their way. These particles flow around the faster jets into the jets’ wake. Thereby, jets stir the magnetosheath, changing the properties of this key region whose particles and magnetic fields can directly interact with the Earth’s magnetic field.
Tomas Karlsson, Ferdinand Plaschke, Heli Hietala, Martin Archer, Xóchitl Blanco-Cano, Primož Kajdič, Per-Arne Lindqvist, Göran Marklund, and Daniel J. Gershman
Ann. Geophys., 36, 655–677, https://doi.org/10.5194/angeo-36-655-2018, https://doi.org/10.5194/angeo-36-655-2018, 2018
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We have studied fast plasma jets outside of Earth’s magnetic environment. Such jets are small-scale structures with a limited lifetime, which may be important in determining the properties of the near-Earth space environment, due to their concentrated kinetic energy. We have used data from the NASA Magnetospheric MultiScale (MMS) satellites to study their properties in detail, to understand how these jets are formed. We have found evidence that there are at least two different types of jets.
Owen W. Roberts, Yasuhito Narita, and C.-Philippe Escoubet
Ann. Geophys., 36, 527–539, https://doi.org/10.5194/angeo-36-527-2018, https://doi.org/10.5194/angeo-36-527-2018, 2018
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In this study we use multi-point spacecraft measurements of magnetic field and electron density derived from spacecraft potential to investigate the three-dimensional structure of solar wind plasma turbulence. We see that there is a dependence on the plasma beta (ratio of thermal to magnetic pressure) as well as a dependence on the type of wind i.e. fast or slow.
Yasuhito Narita and Zoltán Vörös
Ann. Geophys., 36, 101–106, https://doi.org/10.5194/angeo-36-101-2018, https://doi.org/10.5194/angeo-36-101-2018, 2018
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Electromotive force plays a central role in the dynamo mechanism amplifying the magnetic field in turbulent plasmas and electrically conducting fluids. An algorithm is developed to measure the electromotive force using spacecraft data, and it is applied to a magnetic cloud event in interplanetary space. The electromotive force is enhanced when the magnetic cloud passes by the spacecraft, indicating local amplification of the magnetic field.
Owen W. Roberts, Yasuhito Narita, and C.-Philippe Escoubet
Ann. Geophys., 36, 47–52, https://doi.org/10.5194/angeo-36-47-2018, https://doi.org/10.5194/angeo-36-47-2018, 2018
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To investigate compressible plasma turbulence in the solar wind on proton kinetic scales, a high time resolution measurement of the density is obtained from the spacecraft potential. Correlation between the magnetic field strength and the density is investigated as is the rotation sense of the magnetic field. The analysis reveals that compressible fluctuations are characteristic of kinetic Alfvén waves or a mixture of kinetic Alfvén and kinetic slow waves which counter-propagate.
Yasuhito Narita and Zoltán Vörös
Nonlin. Processes Geophys., 24, 673–679, https://doi.org/10.5194/npg-24-673-2017, https://doi.org/10.5194/npg-24-673-2017, 2017
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A method is proposed to determine the temporal decay rate of turbulent fluctuations, and is applied to four-point magnetic field data in interplanetary space. The measured decay, interpreted as the energy transfer rate in turbulence, is larger than the theoretical estimate from the fluid turbulence theory. The faster decay represents one of the differences in turbulent processes between fluid and plasma media.
Sudong Xiao, Tielong Zhang, Guoqiang Wang, Martin Volwerk, Yasong Ge, Daniel Schmid, Rumi Nakamura, Wolfgang Baumjohann, and Ferdinand Plaschke
Ann. Geophys., 35, 1015–1022, https://doi.org/10.5194/angeo-35-1015-2017, https://doi.org/10.5194/angeo-35-1015-2017, 2017
Yasuhito Narita
Nonlin. Processes Geophys., 24, 203–214, https://doi.org/10.5194/npg-24-203-2017, https://doi.org/10.5194/npg-24-203-2017, 2017
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Various methods in the single-spacecraft data analysis are reviewed to determine physical properties of waves, turbulent fluctuations, and wave-wave and wave-particle interactions in the space plasma environment using the magnetic field, the electric field, and the plasma data.
Yasuhito Narita, Yoshihiro Nishimura, and Tohru Hada
Ann. Geophys., 35, 639–644, https://doi.org/10.5194/angeo-35-639-2017, https://doi.org/10.5194/angeo-35-639-2017, 2017
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An algorithm is proposed to estimate the spectral index of the turbulence energy spectrum directly in the wavenumber domain using multiple-sensor-array data. In contrast to the conventional method using time series data and Fourier transform of the fluctuation energy onto the frequency domain, the proposed algorithm does not require the assumption of Taylor's frozen inflow hypothesis, enabling direct comparison of the spectra in the wavenumber domain with various theoretical predictions.
Yasuhito Narita
Ann. Geophys., 35, 325–331, https://doi.org/10.5194/angeo-35-325-2017, https://doi.org/10.5194/angeo-35-325-2017, 2017
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In situ spacecraft data in space plasma are obtained often as time series data. Using Taylor's frozen-in flow hypothesis, one can interpret the time series data as spatial variations swept by the slow and passing by the spacecraft. A quantitative method for estimating the error for Taylor's hypothesis is developed here.
Dennis Frühauff, Ferdinand Plaschke, and Karl-Heinz Glassmeier
Ann. Geophys., 35, 117–121, https://doi.org/10.5194/angeo-35-117-2017, https://doi.org/10.5194/angeo-35-117-2017, 2017
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Vector magnetic field instruments mounted on spacecraft require precise in-flight calibration of the offsets of all three axes, i.e., the output in vanishing ambient field. While calibration of the spin plane offsets is trivial, we apply a new technique for determining the spin axis offset, not relying on solar wind data but on magnetosheath encounters. This technique is successfully applied to the satellites of the THEMIS mission to update the calibration parameters of the complete mission.
Martin Volwerk, Daniel Schmid, Bruce T. Tsurutani, Magda Delva, Ferdinand Plaschke, Yasuhito Narita, Tielong Zhang, and Karl-Heinz Glassmeier
Ann. Geophys., 34, 1099–1108, https://doi.org/10.5194/angeo-34-1099-2016, https://doi.org/10.5194/angeo-34-1099-2016, 2016
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The behaviour of mirror mode waves in Venus's magnetosheath is investigated for solar minimum and maximum conditions. It is shown that the total observational rate of these waves does not change much; however, the distribution over the magnetosheath is significantly different, as well as the growth and decay of the waves during these different solar activity conditions.
David Fischer, Werner Magnes, Christian Hagen, Ivan Dors, Mark W. Chutter, Jerry Needell, Roy B. Torbert, Olivier Le Contel, Robert J. Strangeway, Gernot Kubin, Aris Valavanoglou, Ferdinand Plaschke, Rumi Nakamura, Laurent Mirioni, Christopher T. Russell, Hannes K. Leinweber, Kenneth R. Bromund, Guan Le, Lawrence Kepko, Brian J. Anderson, James A. Slavin, and Wolfgang Baumjohann
Geosci. Instrum. Method. Data Syst., 5, 521–530, https://doi.org/10.5194/gi-5-521-2016, https://doi.org/10.5194/gi-5-521-2016, 2016
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This paper describes frequency and timing calibration, modeling and data processing and calibration for MMS magnetometers, resulting in a merged search choil and fluxgate data product.
Horia Comişel, Yasuhiro Nariyuki, Yasuhito Narita, and Uwe Motschmann
Ann. Geophys., 34, 975–984, https://doi.org/10.5194/angeo-34-975-2016, https://doi.org/10.5194/angeo-34-975-2016, 2016
Rudolf A. Treumann, Wolfgang Baumjohann, and Yasuhito Narita
Ann. Geophys., 34, 673–689, https://doi.org/10.5194/angeo-34-673-2016, https://doi.org/10.5194/angeo-34-673-2016, 2016
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In support of low-frequency electromagnetic turbulence we formulate the inverse scattering theory of electromagnetic fluctuations in plasma. Its solution provides the turbulent response function which contains all information of the dynamical causes of the electromagnetic fluctuations. This is of basic interest in any electromagnetic turbulence. It requires measurement of magnetic and electric fluctuations but makes no direct use of the turbulent power spectral density.
Y. Narita, H. Comişel, and U. Motschmann
Ann. Geophys., 34, 591–593, https://doi.org/10.5194/angeo-34-591-2016, https://doi.org/10.5194/angeo-34-591-2016, 2016
Y. Narita, E. Marsch, C. Perschke, K.-H. Glassmeier, U. Motschmann, and H. Comişel
Ann. Geophys., 34, 393–398, https://doi.org/10.5194/angeo-34-393-2016, https://doi.org/10.5194/angeo-34-393-2016, 2016
Y. Narita, R. Nakamura, W. Baumjohann, K.-H. Glassmeier, U. Motschmann, and H. Comişel
Ann. Geophys., 34, 85–89, https://doi.org/10.5194/angeo-34-85-2016, https://doi.org/10.5194/angeo-34-85-2016, 2016
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Four-spacecraft Cluster observations of turbulent fluctuations in the magnetic reconnection region in the geomagnetic tail show for the first time an indication of ion Bernstein waves, electromagnetic waves that propagate nearly perpendicular to the mean magnetic field and are in resonance with ions. Bernstein waves may influence current sheet dynamics in the reconnection outflow such as a bifurcation of the current sheet.
Y. Narita
Ann. Geophys., 33, 1413–1419, https://doi.org/10.5194/angeo-33-1413-2015, https://doi.org/10.5194/angeo-33-1413-2015, 2015
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A lot of efforts have been put into understanding the turbulence structure in space and astrophysical plasmas, in particular how the filamentary structure develops as the length scale of the turbulent fluctuations changes from large to smaller ones. Motivated by the recent spacecraft observations in the solar wind, an analytic model is proposed to explain the nature of filament-formation processes in space plasma turbulence with a successful test against the spacecraft observations.
H. Comişel, Y. Narita, and U. Motschmann
Ann. Geophys., 33, 345–350, https://doi.org/10.5194/angeo-33-345-2015, https://doi.org/10.5194/angeo-33-345-2015, 2015
H. Comişel, Y. Narita, and U. Motschmann
Nonlin. Processes Geophys., 21, 1075–1083, https://doi.org/10.5194/npg-21-1075-2014, https://doi.org/10.5194/npg-21-1075-2014, 2014
D. Schmid, M. Volwerk, F. Plaschke, Z. Vörös, T. L. Zhang, W. Baumjohann, and Y. Narita
Ann. Geophys., 32, 651–657, https://doi.org/10.5194/angeo-32-651-2014, https://doi.org/10.5194/angeo-32-651-2014, 2014
M. Wilczek, H. Xu, and Y. Narita
Nonlin. Processes Geophys., 21, 645–649, https://doi.org/10.5194/npg-21-645-2014, https://doi.org/10.5194/npg-21-645-2014, 2014
R. Nakamura, F. Plaschke, R. Teubenbacher, L. Giner, W. Baumjohann, W. Magnes, M. Steller, R. B. Torbert, H. Vaith, M. Chutter, K.-H. Fornaçon, K.-H. Glassmeier, and C. Carr
Geosci. Instrum. Method. Data Syst., 3, 1–11, https://doi.org/10.5194/gi-3-1-2014, https://doi.org/10.5194/gi-3-1-2014, 2014
Y. Narita
Nonlin. Processes Geophys., 21, 41–47, https://doi.org/10.5194/npg-21-41-2014, https://doi.org/10.5194/npg-21-41-2014, 2014
C. Perschke, Y. Narita, S. P. Gary, U. Motschmann, and K.-H. Glassmeier
Ann. Geophys., 31, 1949–1955, https://doi.org/10.5194/angeo-31-1949-2013, https://doi.org/10.5194/angeo-31-1949-2013, 2013
F. Plaschke, H. Hietala, and V. Angelopoulos
Ann. Geophys., 31, 1877–1889, https://doi.org/10.5194/angeo-31-1877-2013, https://doi.org/10.5194/angeo-31-1877-2013, 2013
Y. Narita, R. Nakamura, and W. Baumjohann
Ann. Geophys., 31, 1605–1610, https://doi.org/10.5194/angeo-31-1605-2013, https://doi.org/10.5194/angeo-31-1605-2013, 2013
C. Nabert, K.-H. Glassmeier, and F. Plaschke
Ann. Geophys., 31, 419–437, https://doi.org/10.5194/angeo-31-419-2013, https://doi.org/10.5194/angeo-31-419-2013, 2013
Short summary
Spacecraft-mounted magnetic field instruments (magnetometers) need to be routinely calibrated. This involves determining the magnetometer outputs in vanishing ambient magnetic fields, the so-called offsets. We introduce and test a new method to determine these offsets with high accuracy, the mirror mode method, which is complementary to existing methods. The mirror mode method should be highly beneficial to current and future magnetic field observations near Earth, other planets, and comets.
Spacecraft-mounted magnetic field instruments (magnetometers) need to be routinely calibrated....
