ST2.1 | Open Session on the Magnetosphere
EDI
Open Session on the Magnetosphere
Including Julius Bartels Medal Lecture
Convener: Yulia Bogdanova | Co-convener: C.-Philippe Escoubet
Orals
| Wed, 26 Apr, 10:45–12:30 (CEST)
 
Room E2, Thu, 27 Apr, 08:30–10:15 (CEST)
 
Room 1.61/62
Posters on site
| Attendance Thu, 27 Apr, 10:45–12:30 (CEST)
 
Hall X4
Posters virtual
| Attendance Thu, 27 Apr, 10:45–12:30 (CEST)
 
vHall ST/PS
Orals |
Wed, 10:45
Thu, 10:45
Thu, 10:45
This open session traditionally invites presentations on all aspects of the Earth’s magnetospheric physics, including the magnetosphere and its boundary layers, magnetosheath, bow shock and foreshock as well as solar wind-magnetosphere-ionosphere coupling. We welcome contributions on various aspects of magnetospheric observations, remote sensing of the magnetosphere’s processes, modelling and theoretical research. The presentations related to the current and planned space missions and to the value-added data services are also encouraged. This session is suitable for any contribution which does not fit more naturally into one of the specialised sessions and for contributions of wide community interest.

Orals: Wed, 26 Apr | Room E2

Chairpersons: Yulia Bogdanova, C.-Philippe Escoubet
10:45–10:50
10:50–11:00
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EGU23-1390
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ECS
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Highlight
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On-site presentation
Yann Pfau-Kempf, Urs Ganse, Konstantinos Papadakis, Markku Alho, Markus Battarbee, Giulia Cozzani, Maxime Dubart, Harriet George, Evgeniy Gordeev, Maxime Grandin, Konstantinos Horaites, Leo Kotipalo, Jonas Suni, Vertti Tarvus, Fasil Tesema, Lucile Turc, Ivan Zaitsev, Hongyang Zhou, and Minna Palmroth

Vlasiator, the global hybrid-Vlasov model of the terrestrial magnetosphere, now features a coupled ionosphere model replacing the previous, perfectly conducting inner boundary. Following a well-established approach, densities, temperatures and field-aligned currents are mapped along the geomagnetic dipole field down to an ionospheric grid. Height-integrated Hall and Pedersen conductivities are computed using a model atmospheric profile based on the NRLMSIS model in order to solve for the ionospheric potential. Its gradient is then mapped back to the hybrid-Vlasov simulation domain, yielding an electric field and a resulting EXB drift affecting the plasma at the boundary.

We present an overview of this new coupled ionosphere module as well as highlights from the first large-scale magnetospheric simulation runs performed with it. In particular, we compare the global behaviour of the magnetosphere under steady southward interplanetary magnetic field driving using the perfectly conducting or coupled ionosphere boundary models.

How to cite: Pfau-Kempf, Y., Ganse, U., Papadakis, K., Alho, M., Battarbee, M., Cozzani, G., Dubart, M., George, H., Gordeev, E., Grandin, M., Horaites, K., Kotipalo, L., Suni, J., Tarvus, V., Tesema, F., Turc, L., Zaitsev, I., Zhou, H., and Palmroth, M.: First results on global hybrid-Vlasov magnetospheric simulations with a coupled ionosphere, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1390, https://doi.org/10.5194/egusphere-egu23-1390, 2023.

11:00–11:10
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EGU23-16752
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ECS
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On-site presentation
Shiva Kavosi and Katariina Nykyri

Kelvin–Helmholtz instability (KHI) plays a crucial role in solar wind plasma entry into the magnetosphere during the period of northward interplanetary magnetic field (IMF). Several studies have revealed the existence of dawn-dusk asymmetry of KHI along the Earth's magnetopause. However, the causes for such asymmetry are still speculative. Here we survey 11 years of in situ data from the NASA THEMIS (Time History of Events and Macro scale Interactions during Substorms) and MMS (Magnetospheric Multiscale) missions. We found that Kelvin–Helmholtz waves (KHWs) occurrence rates and locations exhibit a semiannual variation; the rate maximizes at the equinoxes and minimizes at the solstice. The rate varies for different IMF By polarities; it is maximum around the fall equinox for negative IMF By, while it is maximum around the spring equinox for positive IMF By. It is shown that the dawn-dusk and north-south asymmetry can be attributed to both the dipole tilt angle and the polarity of Interplanetary magnetic fields (IMF) By; KHI in the northern hemisphere favors the dawn sector for positive dipole tilt and the dusk sector for negative dipole tilt and vice versa in the southern hemisphere. This phase of dawn-dusk asymmetry is dependent on the IMF By polarities.

How to cite: Kavosi, S. and Nykyri, K.: Dawn-Dusk Asymmetry of the Kelvin-Helmholtz Waves at Earth's Magnetopause: One Solar cycle data, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16752, https://doi.org/10.5194/egusphere-egu23-16752, 2023.

11:10–11:20
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EGU23-8322
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Highlight
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On-site presentation
Iannis Dandouras

The Earth’s plasmasphere dominates the mass content of the inner magnetosphere. During extended periods of relatively quiet geomagnetic conditions the outer plasmasphere can become diffuse, with a gradual fall-off of plasma density. During increasing magnetospheric activity, however, the plasmasphere is eroded and plumes, forming at the plasmapause and released outwards, constitute a well-established mode for plasmaspheric material release to the Earth’s magnetosphere. These plumes are associated to active periods and the related electric field change. In 1992, Lemaire and Shunk proposed the existence of an additional mode for plasmaspheric material release to the Earth’s magnetosphere: a plasmaspheric wind, steadily transporting cold plasmaspheric plasma outwards across the geomagnetic field lines, even during prolonged periods of quiet geomagnetic conditions. This has been proposed on a theoretical basis. The Cluster spacecraft, that cross the plasmasphere from south to north during their perigee passes, provided for the first time an experimental confirmation of the plasmaspheric wind. This is based on the analysis of ion measurements acquired by the CIS experiment onboard these spacecraft, which allows also to study the plasmaspheric dynamics under various geomagnetic activity conditions. The plasmaspheric wind has been systematically detected in the outer plasmasphere during quiet and moderately active periods, and provides a contribution to the magnetospheric plasma populations outside the Earth’s plasmasphere.

During the early terrestrial evolution (around 2 to 4 billion years ago), when the Earth’s rotation period around its axis was much shorter, the imbalance between gravitational, centrifugal and pressure gradient forces, giving rise to the plasmaspheric wind, should generate much stronger outflows. The plasmapheric wind should then have played an important role in the early evolution of the terrestrial atmosphere, through enhanced atmospheric escape, including the escape of heavy elements (C+, N+, O+). 

 

 

How to cite: Dandouras, I.: Plasmaspheric wind in the Earth’s magnetosphere: contribution to the early evolution of the terrestrial atmosphere, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8322, https://doi.org/10.5194/egusphere-egu23-8322, 2023.

11:20–11:30
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EGU23-16951
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ECS
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Highlight
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On-site presentation
Cecilia Norgren, Norah Kwagala, Michael Hesse, Tai Phan, and Yuri Khotyaintsev

We report an event of intermittent reconnection from the terrestrial magnetotail observed by the Magnetospheric MultiScale mission. First, magnetic reconnection is active, inferred from a field-aligned off-equatorial plasma jet. Over 40 seconds, this jet is replaced by a quiet time interval with dusk-ward diamagnetic ion flow carried by a hot population that persists for about two minutes. During this interval, we observe signs of current sheet thickening followed by thinning. The change in the dawn-dusk current associated with the inferred thickening is provided by changes in the electron flux, and we argue this is a result of momentum conservation. Thereafter, we observe an equatorial jet of hot plasma that gradually builds up before the spacecraft encounter a dipolarization front about 20 seconds later. This first dipolarization front is associated with a transition from a hot pre-existing plasma sheet, to colder plasma of lobe origin. This event showcases behavior during intermittent magnetic reconnection and may help us understand the spatiotemporal evolution of reconnecting regions.

How to cite: Norgren, C., Kwagala, N., Hesse, M., Phan, T., and Khotyaintsev, Y.: Intermittent magnetic reconnection in the magnetotail, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16951, https://doi.org/10.5194/egusphere-egu23-16951, 2023.

11:30–11:40
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EGU23-7317
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On-site presentation
Soboh Alqeeq, olivier Le Contel, patrick Canu, Alessandro Retinò, Thomas Chust, Laurent Mirioni, Alexandre Chuvatin, Rumi Nakamura, Narges Ahmadi, Frederick Wilder, Daniel Gershman, Yuri Khotyaintsev, Per Arne Lindqvist, Robert Ergun, James Burch, Roy Torbert, Stephen Fuselier, Christopher Russell, Hanying Wei, and Robert Strangeway and the MMS team

We carried out a statistical study of 132 Dipolarization Fronts (DFs) events detected by the Magnetospheric Multiscale mission (MMS) during the full 2017 Earth’s magnetotail season. We found that two DF classes can be distinguished: class I (74.4%) corresponds to the standard DF properties and energy dissipation whereas a new class II (25.6%), which includes the six DF discussed in S. Alqeeq et al. 2022, corresponds to a bump of the magnetic field associated with a minimum of the ion and electron pressures and a reversal of the energy conversion process. For both classes we found that ions are mostly decoupled from the magnetic field by the Hall fields. The electron pressure gradient term is also contributing to the ion decoupling and likely responsible for an electron decoupling at DF. Both DF classes show that the energy conversion process in the spacecraft frame is driven by the diamagnetic current dominated by the ion pressure gradient. In the fluid frame, it is driven by the electron pressure gradient. In addition, we have shown that the energy conversion processes are not homogeneous at the electron scale mostly due to the variations of the electric fields for both DF classes.

How to cite: Alqeeq, S., Le Contel, O., Canu, P., Retinò, A., Chust, T., Mirioni, L., Chuvatin, A., Nakamura, R., Ahmadi, N., Wilder, F., Gershman, D., Khotyaintsev, Y., Lindqvist, P. A., Ergun, R., Burch, J., Torbert, R., Fuselier, S., Russell, C., Wei, H., and Strangeway, R. and the MMS team: Two classes of magnetotail Dipolarization Fronts observed by MagnetosphericMultiscale Mission: A statistical overview, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7317, https://doi.org/10.5194/egusphere-egu23-7317, 2023.

11:40–11:50
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EGU23-7930
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ECS
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Highlight
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On-site presentation
Martin Hosner, Rumi Nakamura, Daniel Schmid, Takuma Nakamura, Evgeny V. Panov, Martin Volwerk, Zoltan Vörös, Owen W. Roberts, Kevin A. Blasl, Adriana Settino, Daniil Korovinskiy, Andrew T. Marshall, and Richard E. Denton and the MMS and Cluster Team

Magnetic reconnection, a key energy conversion process in the Earth’s magnetosphere, has extensively been studied during the last few decades. Multi-point missions such as Cluster or Magnetospheric Multiscale (MMS) showed that magnetic reconnection takes place not only at large-scale stable magnetopause or magnetotail current sheets but also in transient localized current sheets.

Here, we revisit the Dipolarization Front (DF) event, observed by the MMS spacecraft on September 08, 2018/14:51:30 UT in the Earth’s magnetotail. Previous studies reported that this DF shows a strong non-ExB type electron flow and a crescent-shaped distribution function, suggesting that this DF hosts an electron diffusion region (Marshall et al. JGR, 2020).

To further characterize this special event, we (1) use conjunction observations of the MMS and Cluster spacecraft to investigate the event in the context of large scales and (2) apply the polynomial magnetic field reconstruction technique by Denton et al. (JGR, 2020) to characterize the embedded electron current sheet including its velocity and the X-line exhaust opening angle. 

How to cite: Hosner, M., Nakamura, R., Schmid, D., Nakamura, T., Panov, E. V., Volwerk, M., Vörös, Z., Roberts, O. W., Blasl, K. A., Settino, A., Korovinskiy, D., Marshall, A. T., and Denton, R. E. and the MMS and Cluster Team: Electron diffusion region embedded in a dipolarization front – an MMS/Cluster conjunction event, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7930, https://doi.org/10.5194/egusphere-egu23-7930, 2023.

11:50–11:55
11:55–12:25
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EGU23-8054
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solicited
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Julius Bartels Medal Lecture
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On-site presentation
Hermann Opgenoorth

Early studies of “geo-magnetism” dealt with the understanding of long-term developments and short-term disturbances in the geo-magnetic field as measured by magnetometers on ground level. Soon after the IGY the concept of several co-existing and globally or locally interacting ionospheric current systems (DP1 & 2) was born. Both systems seemed to respond differently to solar wind driving conditions and internal magnetospheric processes. Through continued global international study efforts, like e.g. the International Magnetospheric Study (IMS) and later the International Solar Terrestrial Physics program (ISTP) the 2-dimenional monitoring of geomagnetic “disturbances”, now understood as complex signatures of different current systems within and beyond the upper atmosphere, became a powerful tool to monitor and study the complicated three-dimensional coupling of the magnetosphere to the upper atmosphere and its ultimate relation to certain solar wind drivers of magnetospheric conditions.

 

Geomagnetic observations, both globally and regionally, are today a valuable asset to put the very local measurements of magnetospheric satellites (even if “multi-point”) into its proper context with respect to the dynamics of the magnetosphere. The ultimate goal of such measurements today is not only to identify the energy and activity state of the magnetosphere as such, but also to study the exact location, strength and spatio-temporal development of the most powerful short-lived magnetic disturbances that we know, the so-called magnetospheric substorms and the closely related intensifications of major magnetic storms.

 

The study of the physics of the geo-space environment in response to solar activity and solar wind driving has over the last twenty years matured to make first useful predictions of a large variety of plasma processes in near-Earth space, which have the potential to detrimentally affect human space exploration and human technological infrastructure both on ground and in space. The fast-growing research and operational field of Space Weather has stimulated new active research (including advanced model efforts) to get to the bottom of some of the most effective geo-space plasma phenomena, and to understand the variability of ionospheric currents, and their connection to the outer magnetosphere. This is at present one of the most intriguing scientific problems in the field of Space Weather. Potentially any conducting infrastructure on the ground can be detrimentally or catastrophically affected by fast changes in the magnetic field (dB/dt) via geomagnetically induced currents (GICs). In parallel, the involved ionospheric current systems can cause further secondary impacts on space-borne communication and navigations systems via ionospheric plasma instabilities and atmospheric drag effects on satellite orbits.

 

In my presentation I will give a short background to the historical progress of space science with the help of magnetometer data, and then highlight a selection of recent research topics, where global and regional magnetometer networks (together with a multitude of dedicated space missions) represent a very important part of the systematic and coordinated study of the near-Earth plasma environment, the coupled solar wind - magnetosphere - ionosphere – atmosphere “System of Systems”.

How to cite: Opgenoorth, H.: From Geomagnetism and Space Science to Space Weather, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8054, https://doi.org/10.5194/egusphere-egu23-8054, 2023.

12:25–12:30

Orals: Thu, 27 Apr | Room 1.61/62

Chairpersons: C.-Philippe Escoubet, Yulia Bogdanova
08:30–08:35
08:35–08:45
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EGU23-5992
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Virtual presentation
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Martin Archer, David Southwood, and Michael Hartinger

Magnetohydrodynamic (MHD) wave theory states that fast magnetosonic waves should have correlated fluctuations in the compressional magnetic field and the plasma density / pressure. Anticorrelation, on the other hand relates either to the slow magnetosonic or mirror modes. These classic results are often used as a diagnostic in waves observed by spacecraft throughout the heliosphere. However, it is important to recognise that they are derived under the assumption of a homogeneous background plasma. Planetary magnetospheres are, in contrast, highly inhomogeneous. When allowing for a non-uniform background, the linearised MHD equations for density and pressure perturbations include terms due to the intrinsic compression associated with the wave as well as advection of plasma parcels with different background values. We argue that these two effects can compete and result in anticorrelation between the density and magnetic field, particularly when the scale of the inhomogeneity is shorter than that of the wave. We demonstrate examples of this anticorrelation applied to fast-mode magnetopause surface waves in both analytic MHD theory and a global MHD simulation. Finally, methods which identify and allow for these effects in satellite observations are discussed.

How to cite: Archer, M., Southwood, D., and Hartinger, M.: Anticorrelation of density and magnetic field in a fast magnetosonic mode: The case of surface waves in an inhomogeneous magnetosphere, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5992, https://doi.org/10.5194/egusphere-egu23-5992, 2023.

08:45–08:55
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EGU23-14602
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ECS
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On-site presentation
Leonard Schulz, Ferdinand Plaschke, Karl-Heinz Glassmeier, Uwe Motschmann, Yasuhito Narita, Minna Palmroth, Owen Roberts, and Lucile Turc

The wave telescope is a multi-spacecraft method that uses multi-point magnetic field data to estimate a spectrum in k-space, allowing for the detection of waves as well as turbulence. So far, the wave telescope has been applied to the Cluster and MMS four-spacecraft missions around Earth. In the future, it can be used for multi-scale plasma missions incorporating larger numbers of spacecraft. Such are the accepted Helioswarm mission as well as the proposed Plasma Observatory. Due to the more complicated nature of the wave telescope analysis of multi-scale spacecraft configurations, there is a need to study such systems beforehand using as-realistic-as-possible artificial data. Such an artificial 2D or 3D dataset can be provided by Vlasiator, a Hybrid-Vlasov global magnetospheric simulation treating electrons as a fluid and protons being described by distribution functions. We apply the wave telescope to spacecraft configurations both different in number and position and determine the quality of detection of foreshock plasma waves simulated by Vlasiator.

How to cite: Schulz, L., Plaschke, F., Glassmeier, K.-H., Motschmann, U., Narita, Y., Palmroth, M., Roberts, O., and Turc, L.: Application of the wave telescope to Vlasiator simulations using multi-scale spacecraft configurations, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14602, https://doi.org/10.5194/egusphere-egu23-14602, 2023.

08:55–09:05
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EGU23-8132
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ECS
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Highlight
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On-site presentation
Michael J. Starkey, Maher A. Dayeh, Stephen A. Fuselier, Steven M. Petrinec, David J. McComas, Keiichi Ogasawara, Jamey R. Szalay, Nathan A. Schwadron, and Justyna M. Sokół

The solar wind is heated and decelerated by Earth’s bow shock, resulting in a hot and dense population of magnetosheath ions. This increases the production of energetic neutral atoms (ENAs) in this region, which enables the global imaging of Earth’s magnetosheath using ENA imagers onboard the IBEX spacecraft. Furthermore, since these ENAs are unaffected by electromagnetic forces, they carry information about the inherent properties of the progenitor plasma.       
In this work, ENA fluxes from the subsolar magnetosheath, observed by the IBEX spacecraft, are compared to solar wind (SW) conditions. These comparisons reveal that the flux of ENAs is strongly influenced by the SW density, speed, and temperature. Furthermore, evidence of the specularly reflected proton population in the magnetosheath is observed by comparing ENA spectra for different interplanetary magnetic field configurations. This work provides observational constraints to modeling and theoretical work on ENAs from Earth's subsolar magnetosheath and shows that ENAs from Earth's magnetosheath are reflective of their parent ion populations in the magnetosheath.

How to cite: Starkey, M. J., Dayeh, M. A., Fuselier, S. A., Petrinec, S. M., McComas, D. J., Ogasawara, K., Szalay, J. R., Schwadron, N. A., and Sokół, J. M.: Solar Wind Impact on ENAs from Earth’s Subsolar Magnetosheath, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8132, https://doi.org/10.5194/egusphere-egu23-8132, 2023.

09:05–09:15
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EGU23-1632
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On-site presentation
Justyna M. Sokol, Michael Starkey, Maher Dayeh, Stephen Fuselier, Steve Petrinec, David McComas, Nathan Schwadron, Jamey Szalay, and Keiichi Ogasawara

The in-ecliptic solar wind influences the boundaries of the Earth’s magnetosphere, e.g., by controlling the distances of the magnetopause and bow shock. The exospheric neutral hydrogen has been measured up to the Moon’s orbit. The charge exchange between the solar wind protons and the neutral geocoronal hydrogen creates an energetic neutral atom (ENA). The field-of-view of the IBEX-Hi instrument onboard the Interstellar Boundary Explorer (IBEX) encompasses various portions of the Earth’s magnetosphere during the year, including the subsolar point. Recently, Sokół et al. 2021 (ApJ 922 250) reported periodic, solar cycle enhancements of the solar wind dynamic pressure. We study the solar cycle evolution of the H ENA flux in the subsolar magnetosheath based on the IBEX measurements. We observed an enhancement of the ENA flux after the maximum of solar activity. We also analyze how the ENA flux varies with the solar wind parameters. We observe positive correlations with the solar wind dynamic pressure in the energy range from 0.7 to 4.3 keV and also opposite variations in correlation coefficients between the ENA flux and the solar wind speed and density.

How to cite: Sokol, J. M., Starkey, M., Dayeh, M., Fuselier, S., Petrinec, S., McComas, D., Schwadron, N., Szalay, J., and Ogasawara, K.: Solar Cycle Variation of Energetic Neutral Atoms in the Subsolar Magnetosheath based on IBEX Observations, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1632, https://doi.org/10.5194/egusphere-egu23-1632, 2023.

09:15–09:35
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EGU23-12911
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solicited
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Highlight
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On-site presentation
Heli Hietala

The downstream region of a collisionless quasi-parallel shock is structured containing localized bulk flows with high kinetic energy density and dynamic pressure. In 2009, we presented Cluster multi-spacecraft measurements of this type of supermagnetosonic jet as well as of a weak secondary shock within the sheath. These observations allowed us to propose the following generation mechanism for the jets: The local curvature variations inherent to quasi-parallel shocks can create fast, slightly deflected jets accompanied by density variations in the downstream region. If the speed of the jet is super(magneto)sonic in the reference frame of the surrounding flow and/or the magnetopause, a second shock front forms in the sheath.

During the following years, magnetosheath jets have been a continually active research topic. Studies using increasingly large databases of spacecraft observations have gathered the statistics of jet formation conditions and properties. Simulations and case studies have shed light on jet formation mechanisms. Within the magnetosheath, the jet-driven secondary bow waves/shocks have been shown to contribute to particle energization. Investigations of jet impacts on the magnetosphere have revealed a plethora of effects, ranging from surface waves and magnetopause reconnection to diffuse auroral brightenings.

In this talk, we will summarize the progress to date and highlight some still open questions.

How to cite: Hietala, H.: Jets downstream of the Earth’s bow shock, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12911, https://doi.org/10.5194/egusphere-egu23-12911, 2023.

09:35–09:45
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EGU23-3702
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On-site presentation
Karlheinz Trattner, Stephen Fuselier, Steven Petrinec, Jim Burch, and Robert Ergun

Across the Earth’s magnetopause, magnetic reconnection has been observed as either the anti-parallel and/or component reconnection scenarios. The magnetic reconnection location prediction model known as the Maximum Magnetic Shear model combines these two scenarios and predicts long reconnection lines crossing the dayside magnetopause along a ridge of maximum magnetic shear. The model has been tested and validated and predicts the dayside reconnection location correctly for 84% of the events. 
Observed magnetic reconnection events for which the model fails share common characteristics, which indicates that for these conditions additional factors have an influence on the location of the dayside reconnection line. One of these specific conditions results in a set of so-called Knee events for which the anti-parallel reconnection region lines up along the draped Interplanetary Magnetic Field (IMF) lines. For these events, magnetic reconnection remains in the anti-parallel reconnection region as long as it is crossed by the draped IMF. Compared to the usual events, this effect results in a deflection of the connection points between the anti-parallel and component reconnection regions (known as anchor points). This study investigates if the location of the entire component reconnection line or only the anchor points are affected by this deflection.  Using two Knee events with confirmed magnetic reconnection location observed by MMS, this study describes how the entire component reconnection line across the dayside magnetopause is deflected if the relative magnetic shear between the maximum magnetic shear location and the deflected magnetic shear location is less than ~5°. 

How to cite: Trattner, K., Fuselier, S., Petrinec, S., Burch, J., and Ergun, R.: Systemic solar wind condition causing distortion of the predicted magnetic reconnection location at the dayside magnetopause as observed by MMS, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3702, https://doi.org/10.5194/egusphere-egu23-3702, 2023.

09:45–09:55
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EGU23-6951
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ECS
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On-site presentation
Mohammed Baraka, Olivier Le Contel, Patrick Canu, Soboh Alqeeq, Mojtaba Akhavan-Tafti, Alessandro Retino, Thomas Chust, Emanuele Cazzola, Dominique Fontaine, Sergio Toledo-Redondo, Jeremy Dargent, Giulia Cozzani, and Cecilia Norgren and the MMS Team

Magnetic reconnection is a fundamental process that is ubiquitous in the universe and allows the conversion of magnetic field energy into heating and acceleration of plasma. It is responsible for the dominant transport of plasma, momentum, and energy across the magnetopause from the solar wind into the Earth's magnetosphere. The present study reports on a magnetic reconnection event detected by the Magnetospheric Multiscale mission (MMS) on 21 October 2015 around 04:40 UT far from the diffusion regions and related to a large-scale solar wind (SW) perturbation impacting the Earth’s magnetosphere. Based on OMNI data, the event impacting the Earth’s magnetosphere is ahead of weak Stream Interacting Region (SIR) (SW beta≈7 and Alfvénic Mach number≈15) where the averaged density of solar wind is about ~20 cm-3 (compared with average SW density ~3-10 cm-3). On one hand, the magnetosheath (MSH) density measured by MMS just after the crossing of the magnetosphere separatrix layer (identified by the large decrease of energetic electrons fluxes) is very large ~95 cm-3 (compared with average MSH density ~20 cm-3). In such a condition, we show that the current density at this separatrix is dominated by the ion diamagnetic current. On the other hand, cold ions are detected close to the magnetic reconnection separatrix layer on the magnetosphere side. Their origin and impact on the ongoing reconnection process are investigated/discussed. The drifting cold ions and the presence of a guide field have significant effects on the orientation of the electric field normal to the magnetopause.

How to cite: Baraka, M., Le Contel, O., Canu, P., Alqeeq, S., Akhavan-Tafti, M., Retino, A., Chust, T., Cazzola, E., Fontaine, D., Toledo-Redondo, S., Dargent, J., Cozzani, G., and Norgren, C. and the MMS Team: Study of a dayside magnetopause reconnection event detected by MMS related to a large-scale solar wind perturbation and magnetospheric cold ions, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6951, https://doi.org/10.5194/egusphere-egu23-6951, 2023.

09:55–10:05
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EGU23-1189
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On-site presentation
Andrey Samsonov, Natalia Buzulukova, Stephen Milan, Tianran Sun, and Graziella Branduardi-Raymont

We study the magnetospheric response to solar wind discontinuities with a southward interplanetary magnetic field (IMF) turning. We find two events characterized by a strong positive IMF Bz before the discontinuity and a strong negative Bz after the discontinuity. The magnetosphere stays in quiet conditions until the southward turning in both cases, then the dayside reconnection starts and the electromagnetic energy is accumulated in the magnetotail. We simulate these cases using several MHD models and compare numerical predictions of the global parameters such as the magnetopause standoff distance, open flux in the polar cap, auroral indices, and cross polar cap potential. We also make several runs of one model with different spatial resolutions and ionospheric conductivities. Summarizing this study, we discuss the differences between the MHD models and speculate about the reasons why one model is able to better predict observations than the other. We also discuss the reasons for different magnetospheric responses observed in two cases.

How to cite: Samsonov, A., Buzulukova, N., Milan, S., Sun, T., and Branduardi-Raymont, G.: Magnetospheric response to southward IMF turning: insights from global models and data analysis, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1189, https://doi.org/10.5194/egusphere-egu23-1189, 2023.

10:05–10:15
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EGU23-14113
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ECS
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Highlight
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On-site presentation
Kristin Pump, Daniel Heyner, Adam Masters, Sophia Zomerdijk-Russell, and Ferdinand Plaschke

Mercury is the smallest an innermost planet of our solar system and has a dipole-dominated internal magnetic field that is relatively weak, very axisymmetric and significantly offset towards north. Through the interaction with the solar wind, this field leads to a magnetosphere. Compared to the magnetosphere of Earth, Mercury’s magnetosphere is smaller and more dynamic.

A semi-empirical magnetospheric model can capture the large-scale magnetospheric structures. Using the residuals between in-situ data and the model prediction we further seek to improve our understanding of the Hermean magnetosphere.
To first order the magnetopause completely separates the magnetosphere from the magnetosheath and thus no magnetic field may penetrate this boundary. In reality, the magnetosheath field may diffuse across the very thin boundary within a finite time. 

Here, we investigate this penetration and compare the different interplanetary field (IMF) components by their ability to enter into Mercury’s Magnetosphere. For this, we use in-situ MESSENGER magnetic field data to estimate the IMF for the time frame with the probe located inside the magnetosphere. The amount of penetration is found by least-square fitting to magnetospheric model results.
First statistical results indicate that the penetration is stronger under southward IMF conditions.

How to cite: Pump, K., Heyner, D., Masters, A., Zomerdijk-Russell, S., and Plaschke, F.: Analysis of IMF penetration into Mercury’s Magnetosphere, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14113, https://doi.org/10.5194/egusphere-egu23-14113, 2023.

Posters on site: Thu, 27 Apr, 10:45–12:30 | Hall X4

Chairpersons: Yulia Bogdanova, C.-Philippe Escoubet
X4.224
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EGU23-1159
|
ECS
Simon Töpfer, Ida Oertel, Vanita Schiron, Yasuhito Narita, Karl-Heinz Glassmeier, Daniel Heyner, Patrick Kolhey, and Uwe Motschmann

The reconstruction of Mercury’s internal magnetic field enables us to take a look into the inner heart of Mercury. In view of the BepiColombo mission, Mercury’s magnetosphere is simulated using a hybrid plasma code, and the
multipoles of the internal magnetic field are estimated from the virtual spacecraft data using three distinct reconstruction methods: the truncated singular value decomposition, the Tikhonov regularization and Capon’s minimum variance projection. The study shows that a precise determination of Mercury’s internal field beyond the octupole up to the dotriacontapole (fifth degree of the multipole expansion) is possible. Especially, Capon’s method provides the most accurate inversion result compared to the Tikhonov regularization and the truncated singular value decomposition.

How to cite: Töpfer, S., Oertel, I., Schiron, V., Narita, Y., Glassmeier, K.-H., Heyner, D., Kolhey, P., and Motschmann, U.: Reconstruction of Mercury’s internal magnetic field beyond the octupole, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1159, https://doi.org/10.5194/egusphere-egu23-1159, 2023.

X4.225
|
EGU23-4486
Gérard M. Chanteur

At least four spacecraft are essential to investigate physical processes in space plasmas. CLUSTER was the first four-spacecraft mission orbiting the Earth, during its life time the size of the tetrahedron has been adjusted between hundred to thousands of kilometers accordingly to various scientific objectives. The size of MMS, the second four-spacecraft mission, is smaller. In the barycentric formalism [1, chapter 14] reciprocal vectors of the tetrahedron play a prominent role for estimating field gradients and analysing the propagation of waves or discontinuities. The method of least squares [1, chapter 12] underlines also the importance of the reciprocal vectors and both methods are identical  for four spacecraft [1, chapter 15], nevertheless, meanwhile the barycentric approach is restricted to four spacecraft, the least squares approach is applicable to any number N of spacecraft, and more, weighted least squares offer a possibility of optimization. Generalized reciprocal vectors for N spacecraft with arbitrary weights have been defined [2] and it was announced [3] that gradients of fields estimated from CLUSTER or MMS observations could be improved by an appropriate choice of weights ; this is wrong, we hereby demonstrate that for N=4 the estimated gradient of a vector field is independant of the weights. This unfortunate false announcement was due to a programming error: an erratum has been recently presented [4]. Discriminating between synchronous and asynchronous measurements by the constellation helps clarifying the tools and their uses. Synchronous data which gather observations of the same vector field by all spacecraft at the same time are used to estimate the spatial gradient of the field, meanwhile asynchronous data gathering observations of the same field made by the spacecraft at different times are used to estimate wave vectors or the propagation of discontinuities. The generalized synchronous position tensor R1, built from the vertices of the constellation, is introduced to analyze synchronous data, meanwhile the generalized asynchronous position tensor R2, built from the couples of vertices of the constellation, is introduced to analyze asynchronous data. It worth noticing that the synchronous analysis can be optimized only for N > 4 and by contrast the asynchronous analysis for any number N of spacecraft. The corresponding generalized synchronous and asynchronous reciprocal vectors q are defined by applying the inverses Q1 and Q2 of R1 and R2 to the position vectors, and their properties are demonstrated. We also give in tensor form the estimated gradient of a vector field satisfying the solenoidal condition, initially given by components in[1, chapter 12] and we discuss briefly the aliasing of waves by the constellation, initially adressed for a tetrahedron in [1, chapter 14].

References

  • Analysis Methods for Multi-Spacecraft Data, ISSI Scientific Report SR-001, Eds. G. Paschmann and P.W. Daly, 1998.
  • Multi-Spacecraft Analysis Methods Revisited, ISSI Scientific Report SR-008, Eds. G. Paschmann and P.W. Daly, 2008.
  • Chanteur, G.M., Abstract D3.2-0004-18 Optimal Field Gradients Derived From Multi-Spacecraft Observations, Scientific Assembly Abstracts, p1243, COSPAR 2018 Pasadena, California, USA.
  • Chanteur, G.M., CLUSTER 22nd Birthday Workshop, November 7- 11, 2022, ESOC, Darmstadt, Germany

How to cite: Chanteur, G. M.: Reciprocal Vectors of an Arbitrary Constellation of Spacecraft for Estimating Gradients and Wave Vectors, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4486, https://doi.org/10.5194/egusphere-egu23-4486, 2023.

X4.226
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EGU23-6231
|
Highlight
Dana Saxonbergová and Zoltán Vörös

We explore relationship between the interplanetary magnetic field configuration and the direction of the solar wind flow analyzing few substorm onset lists, produced by different methods over the few years.  We investigate the impact of upstream conditions, such as the interplanetary magnetic field (IMF) configuration and  the changing direction of the solar wind flow on the occurrence of substorms by using substorm onset lists between time1-time2. Large directional changes in the solar wind flow can result in large-scale windsock motions and current sheet thinnings forcing magnetic reconnection to occur in magnetospheric tail, which consequently can lead to substorm onset. Magnetic reconnection is a process, which can explain fast and energetic releases of plasmas in the tail during southward oriented IMF, leading to energetic substorms. However, it is more difficult to explain substorms which are associated with northward oriented IMF. Here we aim to analyse substorms associated with northward oriented IMF with the additional challenge to understand whether the substorm onsets are externally triggered by some upstream conditions or internally initiated by some instabilities in the magnetotail, observed for example during northward oriented interplanetary magnetic field i.e. in the time when there is no significant flux transfer. For our analysis we use concurrent OMNI data of solar wind, substorm databases, Geotail, THEMIS satellite data and ground base data.

How to cite: Saxonbergová, D. and Vörös, Z.: A statistical study: Relations Between the Directional Changes in Solar Wind Flow and Magnetotail Response, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6231, https://doi.org/10.5194/egusphere-egu23-6231, 2023.

X4.227
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EGU23-7257
|
Highlight
Souhail Dahani, Benoit Lavraud, Vincent Génot, Sergio Toledo-Redondo, Rungployphan Kieokaew, Naïs Fargette, Daniel Gershman, Barbara Giles, Roy Torbert, and Jim Burch

Flux Transfer Events (FTEs) are transient phenomena generated at the dayside magnetopause as a result of magnetic reconnection. FTEs have a significant role in the transfer of momentum and energy into the magnetosphere. We study here, in a multifluid framework, how the energy is converted within FTEs and their surrounding plasma. In particular we investigate how the plasma gains or loses kinetic energy through electric and/or pressure gradient terms. We also investigate the terms that control how the internal energy of the plasma is gained or dissipated through the pressure work term. Using observations from Magnetospheric MultiScale (MMS), we perform a statistical study based on an existing FTE catalog (Fargette et al., 2020). We analyze FTEs with or without internal current sheets. We discuss the contribution of the different terms in the energy conversion process separately for ions and electrons and as a function of location within the FTE. We analyze and compare the results found for FTEs’ intervals with magnetosheath intervals (Wang et al. 2021), taking into account their locations, using probability distribution functions of the various energy terms measured in each interval. This work contributes to a better understanding of energy conversion processes associated with FTEs at the magnetopause.

How to cite: Dahani, S., Lavraud, B., Génot, V., Toledo-Redondo, S., Kieokaew, R., Fargette, N., Gershman, D., Giles, B., Torbert, R., and Burch, J.: Energy Conversion Associated with Flux Transfer Events at Earth’s Magnetopause, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7257, https://doi.org/10.5194/egusphere-egu23-7257, 2023.

X4.228
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EGU23-8390
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ECS
Vertti Tarvus, Lucile Turc, Hongyang Zhou, Giulia Cozzani, Urs Ganse, Yann Pfau-Kempf, Markku Alho, Markus Battarbee, Maxime Dubart, Harriet George, Konstantinos Horaites, Jonas Suni, Fasil Tesema, Ivan Zaitsev, and Minna Palmroth

The presence of a velocity shear layer in a plasma can lead to the development of the Kelvin-Helmholtz instability (KHI). KHI is characterised by the growth of waves that roll up to form non-linear vortices. An example of such velocity shear layer is found at either flank of Earth's magnetopause, where KHI acts a driver of mass and energy transfer from the solar wind into the magnetosphere. Within the rolled-up vortices, kinetic length scales may be attained, allowing vortex-induced magnetic reconnection and kinetic-scale diffusion to operate. In the present study, we have considered the realistic case of a density/temperature jump across the magnetopause and modelled the development of the KHI using a local hybrid-Vlasov simulation with the Vlasiator code. For a case with a northward directed magnetic field, we find that an enhanced ion heat flux arises at vortex boundaries whose thickness approaches the ion gyroscale. Furthermore, the direction of the heat flux vector closely follows the direction of the vortex boundary tangent vector. As such, this signature could provide observational evidence of ion diffusion occurring within KHI, and also information on vortex boundary geometry with single spacecraft data. To validate our results, we compare our simulation run with data from the Magnetospheric Multiscale Mission.

How to cite: Tarvus, V., Turc, L., Zhou, H., Cozzani, G., Ganse, U., Pfau-Kempf, Y., Alho, M., Battarbee, M., Dubart, M., George, H., Horaites, K., Suni, J., Tesema, F., Zaitsev, I., and Palmroth, M.: Ion heat flux associated with the Kelvin-Helmholtz instability in a non-uniform plasma: Numerical hybrid-Vlasov results, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8390, https://doi.org/10.5194/egusphere-egu23-8390, 2023.

X4.229
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EGU23-8439
Liudmyla Kozak, Bohdan Petrenko, Elena Kronberg, Roman Akhmetshyn, and Istvan Ballai

The energy of particles in the Earth's magnetosphere changes significantly when the configuration of the magnetic field lines suddenly changes from stretched to more dipolar (dipolarization). Energy changes can be caused by variation in electric fields,  due to the generation of electrostatic waves, etc. The presence of heavy ions at the heights of the magnetosphere significantly changes the physics of the processes since, in addition to changing the main characteristics of the plasma (temperature, pressure, Alfven velocity thickness of the current/plasma layer), the conditions and rate of development of instabilities (in particular, the Kelvin-Helmholtz instability) and the nature of turbulent processes will change as well.

In this work, the change of ion and electron fluxes is considered and the peculiarities of resonant interaction of charged particles with electromagnetic fluctuations during the dipolarizations are determined.

The data from the Cluster-II mission spacecraft (magnetic field measurements from ferroelectrode magnetometers (FGM) and energetic particle fluxes from RAPID spectrometers) were used for the analysis. The analysis of individual events is carried out, and a statistical consideration of changes in particle fluxes during magnetic field dipolarizations for 2001–2015 is presented.

Among the features of proton fluxes for individual events, an non-correlation between flux changes in different energy channels is recorded (example, the flux at 27 keV is approximately constant, and is peaks in higher energy ranges). Thus, we have a selective non-adiabatic acceleration of a part of a proton spectrum depending on energy. The change of the spectral index for different energy channels and components was studied.

The values of the power of magnetic field oscillations at gyrofrequencies for different ion types obtained by epoch superposition method showed that resonant interactions of ions with low-frequency electromagnetic waves are more significant for "heavier" components. Therefore the ions can effectively be accelerated by the interaction with these waves during the dipolarization.

This work was supported by the grant no. 97742 of the Volkswagen Foundation (VW-Stiftung), the Royal Society International Exchanges Scheme 2021 IES\R1\211177, and BF/30-2021.

How to cite: Kozak, L., Petrenko, B., Kronberg, E., Akhmetshyn, R., and Ballai, I.: Wave-particle interactions in the Earth magnetotail during dipolarization, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8439, https://doi.org/10.5194/egusphere-egu23-8439, 2023.

X4.230
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EGU23-9371
Maher A. Dayeh, Michael J. Starkey, Steven M. Petrinec, Stephen A. Fuselier, Justyna M. Sokół, Keiichi Ogasawara, Jamey R. Szalay, David J. McComas, Eric J. Zirnstein, and Nathan A. Schwadron

The Interstellar Boundary Explorer (IBEX) mission continues to provide energetic neutral atom (ENA) observations of the heliosphere and Earth’s magnetosphere from a global perspective and including spatial, temporal, and energy information. Due to its orbit, IBEX routinely observes the magnetosphere from a side-viewing vantage point, with a field-of-view that is nearly perpendicular to the day-night plane. This enables the construction of composite ENA images at different energies (0.5 – 6.0 keV) for convected solar wind conditions, which provides global insights into different magnetospheric plasma regions and processes.

Earth’s plasma sheet plays a crucial role in the global circulation of plasma throughout the magnetosphere. The structure of the plasma sheet is driven by a combination of effects including interplanetary magnetic field (IMF) and solar wind conditions, internal magnetospheric processes, and Earth’s dipole tilt angle.

This work examines the structure of the plasma sheet in the X-Z geocentric ecliptic plane (GSE) using ENA images from IBEX. The thickness and extent of the plasma sheet is compared for conditions of prolonged northward and southward IMF. We report on a North-South asymmetry in the plasma sheet that is related to the IMF orientation and is driven by a combination of dayside magnetic reconnection effects and high dipole tilt. Results provide evidence of dayside reconnection driving plasma sheet dynamics.

How to cite: Dayeh, M. A., Starkey, M. J., Petrinec, S. M., Fuselier, S. A., Sokół, J. M., Ogasawara, K., Szalay, J. R., McComas, D. J., Zirnstein, E. J., and Schwadron, N. A.: Asymmetry in the Terrestrial Plasma Sheet Driven by Dayside Dynamics, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9371, https://doi.org/10.5194/egusphere-egu23-9371, 2023.

X4.231
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EGU23-9727
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ECS
Artur Benedito Nunes, Jekaterina Gamper, Matthew Friel, Jesper Gjerloev, and Sandra Chapman

A. M. Benedito Nunes (co-first author), J. Gamper (co-first author), M. Friel, J. W. Gjerloev, S.C. Chapman

 

The Newcomb-Benford Law (NBL) prescribes the probability distribution of the first digit of variables under conditions including aggregation. It will not apply where there is strong truncation or a cut-off. We apply it to space weather relevant magnetic field observations and indices for the first time. In upstream solar wind magnetic field OMNI HRO IMF observations we show that the NBL detects the improvement in data quality with the availability of the WIND and later, ACE spacecraft after 1995, in addition to IMP8. The SMR geomagnetic index averages over multiple ground magnetometer time-series and follows the NBL to a consistent high precision across changing solar activity and a ten-fold increase in the number of constituent stations. The AE and SME indices select the extremal signals from a set of stations. AE, which is mostly based on the same stations throughout its record, follows the NBL to a consistent high precision and with weak but statistically significant variation, it follows the NBL less well during relatively strong solar cycle maxima compared to solar minima. Both the number of constituent stations and the station type comprising SME has changed over the SME record. First, in 1996 the number of available stations increased tenfold, but the station type remained homogeneous. The NBL is followed to a consistent high precision through this period, up to 2006. Beyond 2006, new station types are introduced into the composition of SME and this can be seen in an approximately factor of two drop in the precision with which the NBL is followed. Subsequently, the SME record follows the NBL to varying precision which tracks the inclusion and omission of different types of magnetometer in the record. As the use of composite indices becomes more widespread across the geosciences, the NBL may therefore provide a generic 'data flag' to indicate when the constituent raw data, calibration or sampling method has changed.

How to cite: Benedito Nunes, A., Gamper, J., Friel, M., Gjerloev, J., and Chapman, S.: Newcomb-Benford Law characterization of solar wind magnetic field and geomagnetic indices, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9727, https://doi.org/10.5194/egusphere-egu23-9727, 2023.

X4.232
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EGU23-11179
Costel Munteanu, Eliza Teodorescu, and Marius Echim

We search for ESA’s Cluster and NASA’s MMS missions’ simultaneous observations of the Earth’s magnetosheath (MSH) region. Visual inspection of Cluster quicklook plots is used to determine Cluster-MSH crossings. Next, MMS quicklook plots are inspected, and the MMS-MSH crossings which overlap in time with the Cluster-MSH intervals from step 1, are catalogued. We find 117 simultaneous crossings in 2017-2021. Our overall goal is to investigate the correlation between the properties of the magnetosheath and the bow shock (BS) characteristics. Thus, for each one of the MSH intervals in our catalogue, we determine the BS characteristics. The Earth’s bow shock can be classified as either quasi-parallel or quasi-perpendicular, depending on the angle between the interplanetary magnetic field (IMF) and bow shock normal direction. We use OMNI data to determine the IMF direction, and we estimate the BS normal direction using two approaches: (1) from magnetic field measurements using minimum variance analysis and (2) from a bow shock model using solar wind data as input. We will present our catalogue of simultaneous Cluster-MMS magnetosheath crossings, and also our estimates for the BS type associated with each crossing.

How to cite: Munteanu, C., Teodorescu, E., and Echim, M.: Cluster and MMS simultaneous observations of the Earth’s magnetosheath region in 2017-2021, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11179, https://doi.org/10.5194/egusphere-egu23-11179, 2023.

X4.233
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EGU23-12182
Jiwon Choi, Dong-Hun Lee, Kyungguk Min, Kichang Yoon, and Jong Uk Park

Ultra-low frequency (ULF) waves in the Earth’s magnetosphere are commonly observed in space as well as on the ground stations. Located between the magnetosphere and the earth’s surface, the lower-thermosphere-ionosphere region is expected to be abundant in ULF waves. Transverse Alfven waves are of interest since they have one-dimensional nature along the magnetic field lines with radial variation in their characteristic frequencies. We have conducted three-dimensional magnetohydrodynamic wave simulations to investigate ULF observations by various types of low-Earth orbit (LEO) satellites. Virtual spacecraft are embedded in our model to measure electromagnetic wave signals as they move at different altitudes and latitudes. Our results present that the waveform and frequency of transverse waves change significantly when they are observed in low Earth orbit. Since the majority of LEO satellites lay in polar orbit, they traverse different field lines at relatively high speeds. Thus, fast movement through Alfven speed gradient along the spacecraft trajectory alters the frequency of transverse Alfven waves. It is worth noting that the observed frequency by virtual satellites in low-Earth orbit becomes ~8 times higher than the original frequency. It indicates that frequency distortion from LEO satellite observations can cause serious differences between ground-based and satellite observations. We suggest validating ULF wave observations in low-Earth orbit using a series of spacecraft such as the CubeSat constellation can improve the robustness of electromagnetic field measurements in LEO.

How to cite: Choi, J., Lee, D.-H., Min, K., Yoon, K., and Park, J. U.: Validating in-situ measurements of ULF Waves in Low Earth Orbit, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12182, https://doi.org/10.5194/egusphere-egu23-12182, 2023.

X4.234
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EGU23-12541
Evgeny V. Panov, Marina V. Kubyshkina, Victor A. Sergeev, Rumi Nakamura, and Wolfgang Baumjohann

In situ observations revealed both linear and non-linear signatures of the kinetic (electron) ballooning-interchange instability (BICI) operating in the Earth’s magnetotail, which appear to drive auroral beads and pseudo-breakups in the ionosphere. Observation of the magnetotail configurations with inversed gradient of the vertical magnetic field, which is believed to drive the BICI is challenged by sparse spacecraft coverage. We use the adapted modeling based on in situ spacecraft observations, and low-altitude particle observations to extract some information on such magnetotail configurations. We present two in situ events with both linear and non-linear BICI development signatures and compare the magnetotail configurations during the two events using the two methods.

How to cite: Panov, E. V., Kubyshkina, M. V., Sergeev, V. A., Nakamura, R., and Baumjohann, W.: Magnetotail configurations during ballooning-interchange instability signatures, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12541, https://doi.org/10.5194/egusphere-egu23-12541, 2023.

X4.235
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EGU23-12580
Olivier Le Contel, Alessandro Retino, Thomas Chust, Konrad Steinvall, Soboh Alqeeq, Mohammed Baraka, Patrick Canu, Dominique Fontaine, Laurent Mirioni, Iannis Dandouras, Christopher Carr, Sergio Toledo-Redondo, Andrew Fazakerley, Natasha Doss, Patrick Daly, Stefan Kiehas, Rumi Nakamura, Yuri Khotyaintsev, Frederick Wilder, and Narges Ahmadi and the Joint Cluster/MMS team

On 28th of August 2018 at 5:30 UT, MMS and Cluster were located in the magnetotail at about 16 earth radii (RE). They both suddenly crossed plasma interfaces. Located near the post midnight sector, Cluster transitioned from a cold plasma sheet to a hot plasma sheet associated with a quasi-parallel earthward flow 800 km/s whereas MMS, located at 4 RE duskward of Cluster, transitioned from a similar cold plasma sheet to the lobe region via a very short period in a hot plasma sheet associated with a vortex-like signature. At 05:50 UT MMS returned to a hot plasma sheet and also detected a quasi-parallel earthward flow ~ 400 km/s and increased energetic ion and electron fluxes. We use measurements from both missions during this conjunction to describe the possible large scale dynamics of the magnetotail as well as some associated kinetic processes. Energetic particle (>50keV) measurements from the two missions are compared. Furthermore, at ion scales, we investigate the possible role of ion fire-hose instability in the plasma flow reduction. At electron scales, we analyze fast and slow non linear electrostatic waves propagating tailward which are detected in the so called electron boundary layer as well as in the hot plasma sheet. We discuss their possible generation mechanisms and link with the large scale dynamics of the magnetotail.

How to cite: Le Contel, O., Retino, A., Chust, T., Steinvall, K., Alqeeq, S., Baraka, M., Canu, P., Fontaine, D., Mirioni, L., Dandouras, I., Carr, C., Toledo-Redondo, S., Fazakerley, A., Doss, N., Daly, P., Kiehas, S., Nakamura, R., Khotyaintsev, Y., Wilder, F., and Ahmadi, N. and the Joint Cluster/MMS team: Study of kinetic processes based on MMS/Cluster joint measurements in the vicinity of the plasma sheet boundary layer, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12580, https://doi.org/10.5194/egusphere-egu23-12580, 2023.

X4.236
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EGU23-13452
|
ECS
Markku Alho, Markus Battarbee, Leo Kotipalo, Maxime Grandin, Yann Pfau-Kempf, Urs Ganse, Giulia Cozzani, Maarja Bussov, Evgenii Gordeev, Konstantinos Horaites, Fasil Tesema Kebede, Konstantinos Papadakis, Jonas Suni, Vertti Tarvus, Lucile Turc, Ivan Zaitsev, Hongyang Zhou, and Minna Palmroth

Models of the geospace plasma environment have been proceeding towards more realistic descriptions of the solar wind—magnetosphere interaction, from gas-dynamic to MHD and hybrid ion-kinetic models such as the state-of-the-art Vlasiator model. Advances in computational capabilities have enabled global simulations of detailed physics, with some inroads to electron physics made with eVlasiator, specifically, in a meridional 2D+3V simulation.

In this work we present preliminary results from eVlasiator, an offshoot of the Vlasiator model, showing results from a global 3D+3V kinetic electron geospace simulation. Previous work in a spatially 2D environment has shown, despite truncation of some electron physics and use of ion-scale spatial resolution, that realistic electron distribution functions are obtainable within the magnetosphere. This work examines the differences between the spatially 2D and the new spatially 3D results, and describe these in relation to MMS observations. Electron precipitation to the upper atmosphere from these velocity distributions is estimated.

How to cite: Alho, M., Battarbee, M., Kotipalo, L., Grandin, M., Pfau-Kempf, Y., Ganse, U., Cozzani, G., Bussov, M., Gordeev, E., Horaites, K., Kebede, F. T., Papadakis, K., Suni, J., Tarvus, V., Turc, L., Zaitsev, I., Zhou, H., and Palmroth, M.: Global simulation of geospace electrons: eVlasiator in 3D, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13452, https://doi.org/10.5194/egusphere-egu23-13452, 2023.

X4.237
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EGU23-13756
|
ECS
Hongyang Zhou, Lucile Turc, Guilia Cozzani, Ivan Zaitsev, Yann Pfau-Kempf, Konstantinos Horaites, Fasil Kebede, Markus Battarbee, Markku Alho, Maxime Grandin, Evgenii Gordeev, Vertti Tarvus, Maxime Dubart, Jonas Suni, Konstantinos Papadakis, Urs Ganse, and Minna Palmroth

Kinetic Alfvén wave (KAW) is the kinetic extension of shear Alfvén wave (SAW) where the perpendicular wavelength with respect to the magnetic field becomes comparable to the ion scale. It has been suggested theoretically that mode conversion from incident compressional waves to KAWs at the magnetopause leads to the plasma transport. Existence of KAWs has been identified from in-situ observations and shown to be closely related to the Hall field from magnetic reconnection. In this study, we investigate the properties of KAWs using the hybrid-Vlasov model Vlasiator. Local runs of tangential discontinuities with parameters relevant to Earth’s magnetopause are performed to look at the mode conversion from fast waves to Alfvén waves. Signatures of KAWs are identified from both local and global simulations, which provide insights into the nonlinear plasma transport process in the magnetosphere.

How to cite: Zhou, H., Turc, L., Cozzani, G., Zaitsev, I., Pfau-Kempf, Y., Horaites, K., Kebede, F., Battarbee, M., Alho, M., Grandin, M., Gordeev, E., Tarvus, V., Dubart, M., Suni, J., Papadakis, K., Ganse, U., and Palmroth, M.: Kinetic Alfvén waves from hybrid-Vlasov simulations, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13756, https://doi.org/10.5194/egusphere-egu23-13756, 2023.

Posters virtual: Thu, 27 Apr, 10:45–12:30 | vHall ST/PS

Chairpersons: C.-Philippe Escoubet, Yulia Bogdanova
vSP.9
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EGU23-7205
Xiaochao Yang, Lei Dai, Ji Wu, Wen Li, Yoshizumi Miyoshi, Rumi Nakamura, Minna Palmroth, Mohammad Ebrahimi, Li Deng, and Yulun Li

A COnstellation of Radiation BElt Survey (CORBES) program is proposed by the Sub-Group on Radiation Belt (SGRB) of TGCSS, COSPAR, which is in pursuit of the goal of SGRB, focusing on the implementation of a Small/CubeSats constellation mission for radiation belt exploration. Basing on a general review of the status quo of research on the Earth’s radiation belts dynamics and the unresolved scientific issues, the scientific object and observation requirements of CORBES are proposed. The CORBES program is expected to have a constellation of 10-plus small/ CubeSats to take an ultra-fast survey of the Earth’s radiation belt. The general science goal for CORBES is to investigate two groups of physical processes related to the radiation belts: wave-particle interactions and radial transport. This program is an international multilateral cooperation mission, an open and sharing data policy will be implemented. The data set of observations will be shared within the contributors of the constellation and the broad research community at large, then would be of great use for comprehensively understanding the dynamics of magnetospheric energetic populations and developing more standard models of the Earth’s radiation belts. Furthermore, from the application perspective, the ultra-fast survey of the radiation belt could serve as an important facility for monitoring space weather of the Earth as well.

How to cite: Yang, X., Dai, L., Wu, J., Li, W., Miyoshi, Y., Nakamura, R., Palmroth, M., Ebrahimi, M., Deng, L., and Li, Y.: Constellation of radiation belts survey (CORBES) a COSPAR small satellite constellation survey program for Earth’s radiation belt, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7205, https://doi.org/10.5194/egusphere-egu23-7205, 2023.

vSP.10
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EGU23-11764
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ECS
Qusai Al Shidi, Tuija Pulkkinen, and Daniel Welling

We created a database of over 100 simulations of geomagnetic storms from the time interval from 2010 to 2019, using the Geospace configuration of the Space Weather Modeling Framework. With this data set, we explore and quantify the errors that arise from the uncertainties of the input solar wind data set that comes from the OMNI database, using global magnetic indices such as SYM-H, AL and Cross Polar Cap Potential as measures of the model output that can be directly compared with observations. Our results show that the method of propagation of the solar wind data from the spacecraft location near L1 to the bow shock nose causes errors that are much smaller than those arising from the limitations in modeling the solar wind – magnetosphere – ionosphere coupling processes during strong solar wind driving. We devise a method to quantify these uncertainties, which may become useful in understanding the output of global simulations. These results will be useful as well for research investigations of magnetospheric processes as well as for forecasting space weather.

How to cite: Al Shidi, Q., Pulkkinen, T., and Welling, D.: Uncertainty Quantification in Global Simulations: Solar Wind Propagation Effects, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11764, https://doi.org/10.5194/egusphere-egu23-11764, 2023.