scholarly journals Terrestrial ion escape and relevant circulation in space

2019 ◽  
Vol 37 (6) ◽  
pp. 1197-1222 ◽  
Author(s):  
Masatoshi Yamauchi
Keyword(s):  
Solar Wind ◽  
Heavy Ions ◽  
Current System ◽  
Particle Interaction ◽  
Inner Magnetosphere ◽  
Ion Drift ◽  
Ion Escape ◽  
Drift Theory ◽  
Suprathermal Ions ◽  
Mass Dependent

Abstract. Observations of the terrestrial ion escape to space and the transport of escaping ions in the magnetosphere are reviewed, with the main stress on subjects that were not covered in reviews over past 2 decades, during which Cluster has significantly improved our knowledge of them. Here, outflowing ions from the ionosphere are classified in terms of energy rather than location: (1) as cold ions refilling the plasmasphere faster than Jeans escape, (2) as cold supersonic ions such as the polar wind, and (3) as suprathermal ions energized by wave–particle interaction or parallel potential acceleration, mainly starting from cold supersonic ions. The majority of the suprathermal ions above the ionosphere become “hot” at high altitudes, with much higher velocity than the escape velocity even for heavy ions. This makes heavy hot ions more abundant in the magnetosphere than heavy ions transported by cold refilling ions or cold supersonic flow. The immediate destination of these terrestrial ions varies from the plasmasphere, the inner magnetosphere including those entering the ionosphere in the other hemisphere and the tailward outer boundaries, the magnetotail, and the solar wind (magnetosheath, cusp, and plasma mantle). Due to time-variable return from the magnetotail, ions with different routes and energy meet in the inner magnetosphere, making it a zoo of different types of ions in both energy and energy distribution. While the mass-independent drift theory has successfully disentangled this zoo of ions, there are many poorly understood phenomena, e.g., mass-dependent energization. Half of the heavy ions in this zoo also finally escape to space, mainly due to magnetopause shadowing (overshooting of ion drift beyond the magnetopause) and charge exchange near the mirror altitude where the exospheric neutral density is at its highest. The amount of heavy ions mixing directly with the solar wind is already the same as or larger than that entering into the magnetotail and is large enough to extract the solar wind kinetic energy in the cusp–plasma mantle through the mass-loading effect and drive the current system near the cusp independently of the global current system. Considering the past solar and solar wind conditions, ion escape might even have influenced the evolution of the terrestrial biosphere.

scholarly journals Terrestrial ion circulation in space

2019 ◽  
Author(s):  
Masatoshi Yamauchi
Keyword(s):  
Solar Wind ◽  
Heavy Ions ◽  
Current System ◽  
Particle Interaction ◽  
Inner Magnetosphere ◽  
Ion Drift ◽  
Ion Escape ◽  
Drift Theory ◽  
Suprathermal Ions ◽  
Mass Dependent

Abstract. Observations of the terrestrial ion transport and budget in the magnetosphere are reviewed, with stress on low energy ions in the high-altitude polar region and inner magnetosphere, for which Cluster significantly improved the knowledge. Outflowing ions from the ionosphere are classified into three types in terms of energy: (1) as cold ions refilling the plasmasphere faster than Jeans escape, (2) as cold supersonic ions such as the polar wind, and (3) as suprathermal ions energized by wave-particle interaction or parallel potential acceleration. Majority of the suprathermal ions are further energized at higher altitudes becoming hot with much higher velocity than the escape velocity even for heavy ions. This makes heavy ions in this category more abundant than cold refilling or cold supersonic flow. The immediate destination of these terrestrial ions varies from the plasmasphere, the inner magnetosphere including those entering to the ionosphere in the other, the magnetotail, and the solar wind (magnetosheath and cusp/plasma mantle). Due to time variable return from the magnetotail, ions with different routes and energy meet in the inner magnetosphere, making it a zoo of different types of ions in both energy and energy distribution. This zoo is not yet completely entangled, and includes many unanswered phenomena such as mass-dependent energization although the mass-independent drift theory is well justified. Nearly half of heavy ions in this zoo also finally escape to space, mainly due to magnetopause shadowing (overshooting of ion drift beyond the magnetopause) and charge exchange near the mirror altitude where the exospheric neutral density is the highest. The amount of heavy ions mixing with the solar wind is already the same or larger than that into the magnetotail, and is large enough to directly extract the solar wind kinetic energy in the cusp/plasma mantle through the mass-loading effect and drive the cusp current system. Considering the past solar and solar wind conditions, ion escape might have even influenced the evolution of the terrestrial biosphere.

Updates and Early Results from the Heavy Ion Sensor on Solar Orbiter

2021 ◽  
Author(s):  
Susan T. Lepri ◽  
Stefano A. Livi ◽  
Jim M. Raines ◽  
Antoinette B. Galvin ◽  
Lynn M. Kistler ◽  
...  
Keyword(s):  
Solar Wind ◽  
Heavy Ions ◽  
Heavy Ion ◽  
Alpha Particles ◽  
The Sun ◽  
Ion Sensor ◽  
Source Regions ◽  
Early Results ◽  
Public Datasets ◽  
Suprathermal Ions

<p> </p><p>The Solar Orbiter mission was launched in 2020 into an orbit that will explore the inner heliosphere. During its orbit, periods of quasi-corotation with the Sun will enable determination of the source regions on the Sun for solar wind structures.  The Solar Wind Analyser (SWA) is a suite of instruments that provide in-situ measurements of solar wind electrons, protons, alpha particles, and heavy ions.  The SWA-Heavy Ion Sensor (HIS) is optimized to measure heavy ions in the solar wind, pickup ions, and suprathermal ions in an energy range spanning from 0.5- 75keV/e.  We present measurements of heavy ion composition from SWA-HIS taken during the cruise phase of the mission to highlight the capabilities of the instrument and the observations we expect to collect over the next 10 years. We discuss how SWA-HIS will enable linkages between the Sun and the solar wind to reveal the nature of the acceleration and release of the solar wind and the sources and structure of the solar wind.  We will also provide an overview of the available data and accessibility of the public datasets. </p>

MMS Observations of the Charge State and Mass Dependent Energization of Heavy Ions During Injections in the Earth’s Magnetotail

2020 ◽  
Author(s):  
Sam Bingham ◽  
Ian Cohen ◽  
Barry Mauk ◽  
Don Mitchell ◽  
Drew Turner ◽  
...  
Keyword(s):  
Charge State ◽  
Electric Fields ◽  
Heavy Ions ◽  
Inner Magnetosphere ◽  
The Earth ◽  
State Dependent ◽  
Magnetospheric Multiscale ◽  
Charge States ◽  
Solar Wind Origin ◽  
Mass Dependent

<p>Particle injections transport particles from the Earth’s magnetotail to the inner magnetosphere. During this process, ions in the injections are substantially energized. The physical processes behind this energization are still under debate. Recent results from the Van Allen Probes mission at radial distances < 6 R<sub>E</sub> have shown that higher mass ions (helium and oxygen) with high charge states are often found at substantially higher energies than protons (up to MeV energies compared to a couple hundred keV) in the inner magnetosphere. Here we present results from the Magnetospheric Multiscale (MMS) mission over a broad range of radial distances (between 7-25 R<sub>E</sub>) where the energization of injected ions is charge state dependent. We demonstrate with these observations that injected ions exhibit behavior which is well ordered by energy per charge due to the gradient/curvature drift’s impact on particle trajectories as they drift in the direction of transient electric fields. The charge state dependent energization leads to the dominance of multiple charge state heavy ions, as opposed to H<sup>+</sup>, above ~250 keV throughout the Earth’s inner and middle magnetosphere. Additionally, there are also cases with hints of non-adiabatic energization observed in O<sup>+</sup> between ~100-250 keV, where O<sup>+</sup> potentially gets some extra-energization compared to H<sup>+</sup> due differences in their respective gyroradii. However, the highest energy ions (> 300 keV oxygen and helium) are still likely of solar wind origin and primarily accelerated due to their higher charge-state. In the process of these results we demonstrate the utility of a technique for deducing ion charge-states using instrumentation that does not directly discriminate by charge state.</p>

Understanding the controlling factors of Ultra-Low Frequency waves and their penetration during geomagnetic storms

2020 ◽  
Author(s):  
Jonathan Rae ◽  
Kyle Murphy ◽  
Clare Watt ◽  
Jasmine Sandhu ◽  
Samuel Wharton ◽  
...  
Keyword(s):  
Solar Wind ◽  
Radiation Belt ◽  
Ring Current ◽  
Geomagnetic Storms ◽  
Particle Interaction ◽  
Low Frequency ◽  
Controlling Factors ◽  
Wave Power ◽  
Inner Magnetosphere ◽  
Ulf Wave

<p>Wave-particle interactions play a key role in radiation belt dynamics. Traditionally, Ultra-Low Frequency (ULF) wave-particle interaction is parameterised statistically by a small number of controlling factors for given solar wind driving conditions or geomagnetic activity levels. Here, we investigate solar wind driving of ultra-low frequency (ULF) wave power and the role of the magnetosphere in screening that power from penetrating deep into the inner magnetosphere. We demonstrate that, during enhanced ring current intensity, the Alfvén continuum plummets, allowing lower frequency waves to penetrate deeper into the magnetosphere than during quiet periods. With this penetration, ULF wave power is able to accumulate closer to the Earth than characterised by statistical models. During periods of enhanced solar wind driving such as coronal mass ejection driven storms, where ring current intensities maximise, the observed penetration provides a simple physics-based reason for why storm-time ULF wave power is different compared to non-storm time waves. We demonstrate statistically that the ring current plays a pivotal role in allowing ULF wave energy to access the inner magnetosphere and show a new parameterisation of ULF wave power for radiation belt research purposes that is specifically tuned for geomagnetic storms.</p>

scholarly journals MAVEN Observations of Periodic Low-altitude Plasma Clouds at Mars

2021 ◽  
Vol 922 (2) ◽  
pp. L33
Author(s):  
Chi Zhang ◽  
Zhaojin Rong ◽  
Hans Nilsson ◽  
Lucy Klinger ◽  
Shaosui Xu ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Heavy Ions ◽  
Ionospheric Plasma ◽  
Martian Atmosphere ◽  
Mars Atmosphere ◽  
Ion Escape ◽  
Low Altitude ◽  
Field Lines ◽  
Bulk Plasma

Abstract Ion escape to space through the interaction of solar wind and Mars is an important factor influencing the evolution of the Martian atmosphere. The plasma clouds (explosive bulk plasma escape), considered an important ion escaping channel, have been recently identified by spacecraft observations. However, our knowledge about Martian plasma clouds is lacking. Based on the observations of the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft, we study a sequence of periodic plasma clouds that occurred at low altitudes (∼600 km) on Mars. We find that the heavy ions in these clouds are energy-dispersed and have the same velocity, regardless of species. By tracing such energy-dispersed ions, we find the source of these clouds is located in a low-altitude ionosphere (∼120 km). The average tailward moving flux of ionospheric plasma carried by clouds is on the order of 107 cm−2 s−1, which is one order higher than the average escaping flux for the magnetotail, suggesting explosive ion escape via clouds. Based on the characteristics of clouds, we suggest, similar to the outflow of Earth’s cusp, these clouds might be the product of heating due to solar wind precipitation along the open field lines, which were generated by magnetic reconnection between the interplanetary magnetic field and crustal fields that occurred above the source.

scholarly journals Influence of heavy ions on the high-speed solar wind

1997 ◽  
Vol 102 (A8) ◽  
pp. 17419-17432 ◽  
Author(s):  
Xing Li ◽  
Ruth Esser ◽  
Shadia R. Habbal ◽  
You-Qiu Hu
Keyword(s):  
Solar Wind ◽  
Heavy Ions ◽  
High Speed ◽  
Speed Solar Wind ◽  
High Speed Solar Wind

Intense dB/dt variations driven by near-Earth Bursty Bulk Flows (BBFs): A case study

2021 ◽  
Author(s):  
Dong Wei ◽  
Malcolm Dunlop ◽  
Junying Yang ◽  
Xiangcheng Dong ◽  
Yiqun Yu ◽  
...  
Keyword(s):  
Large Scale ◽  
Current System ◽  
Geomagnetically Induced Currents ◽  
Inner Magnetosphere ◽  
Wide Range ◽  
Ground System ◽  
Induced Currents ◽  
Ground Magnetic ◽  
Bursty Bulk Flows

<p>During geomagnetically disturbed times the surface geomagnetic field often changes abruptly, producing geomagnetically induced currents (GICs) in a number of ground based systems. There are, however, few studies reporting GIC effects which are driven directly by bursty bulk flows (BBFs) in the inner magnetosphere. In this study, we investigate the characteristics and responses of the magnetosphere-ionosphere-ground system during the 7 January 2015 storm by using a multi-point approach which combines space-borne measurements and ground magnetic observations. During the event, multiple BBFs are detected in the inner magnetosphere while the magnetic footprints of both magnetospheric and ionospheric satellites map to the same conjugate region surrounded by a group of magnetometer ground stations. It is suggested that the observed, localized substorm currents are caused by the observed magnetospheric BBFs, giving rise to intense geomagnetic perturbations. Our results provide direct evidence that the wide-range of intense dB/dt<strong> </strong>(and dH/dt) variations are associated with a large-scale, substorm current system, driven by multiple BBFs.</p>

scholarly journals Mars Under Primordial Solar Wind Conditions: Mars Express Observations of the Strongest CME Detected at Mars Under Solar Cycle #24 and its Impact on Atmospheric Ion Escape

2017 ◽  
Vol 44 (21) ◽  
Author(s):  
Robin Ramstad ◽  
Stas Barabash ◽  
Yoshifumi Futaana ◽  
Masatoshi Yamauchi ◽  
Hans Nilsson ◽  
...  
Keyword(s):  
Solar Wind ◽  
Solar Cycle ◽  
Mars Express ◽  
Ion Escape ◽  
Solar Cycle 24 ◽  
Cycle 24

scholarly journals Azimuthal magnetic fields in Saturn’s magnetosphere: effects associated with plasma sub-corotation and the magnetopause-tail current system

2003 ◽  
Vol 21 (8) ◽  
pp. 1709-1722 ◽  
Author(s):  
E. J. Bunce ◽  
S. W. H. Cowley ◽  
J. A. Wild
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Magnetic Fields ◽  
Current System ◽  
Heavy Ion ◽  
Local Times ◽  
Dynamical Process ◽  
Tail Current ◽  
Field Lines ◽  
Inner Region

Abstract. We calculate the azimuthal magnetic fields expected to be present in Saturn’s magnetosphere associated with two physical effects, and compare them with the fields observed during the flybys of the two Voyager spacecraft. The first effect is associated with the magnetosphere-ionosphere coupling currents which result from the sub-corotation of the magnetospheric plasma. This is calculated from empirical models of the plasma flow and magnetic field based on Voyager data, with the effective Pedersen conductivity of Saturn’s ionosphere being treated as an essentially free parameter. This mechanism results in a ‘lagging’ field configuration at all local times. The second effect is due to the day-night asymmetric confinement of the magnetosphere by the solar wind (i.e. the magnetopause and tail current system), which we have estimated empirically by scaling a model of the Earth’s magnetosphere to Saturn. This effect produces ‘leading’ fields in the dusk magnetosphere, and ‘lagging’ fields at dawn. Our results show that the azimuthal fields observed in the inner regions can be reasonably well accounted for by plasma sub-corotation, given a value of the effective ionospheric Pedersen conductivity of ~ 1–2 mho. This statement applies to field lines mapping to the equator within ~ 8 RS (1 RS is taken to be 60 330 km) of the planet on the dayside inbound passes, where the plasma distribution is dominated by a thin equatorial heavy-ion plasma sheet, and to field lines mapping to the equator within ~ 15 RS on the dawn side outbound passes. The contributions of the magnetopause-tail currents are estimated to be much smaller than the observed fields in these regions. If, however, we assume that the azimuthal fields observed in these regions are not due to sub-corotation but to some other process, then the above effective conductivities define an upper limit, such that values above ~ 2 mho can definitely be ruled out. Outside of this inner region the spacecraft observed both ‘lagging’ and ‘leading’ fields in the post-noon dayside magnetosphere during the inbound passes, with ‘leading’ fields being observed both adjacent to the magnetopause and in the ring current region, and ‘lagging’ fields being observed between. The observed ‘lagging’ fields are consistent in magnitude with the sub-corotation effect with an effective ionospheric conductivity of ~ 1–2 mho, while the ‘leading’ fields are considerably larger than those estimated for the magnetopause-tail currents, and appear to be indicative of the presence of another dynamical process. No ‘leading’ fields were observed outside the inner region on the dawn side outbound passes, with the azimuthal fields first falling below those expected for sub-corotation, before increasing, to exceed these values at radial distances beyond ~ 15–20 RS , where the effect of the magnetopause-tail currents becomes significant. As a by-product, our investigation also indicates that modification and scaling of terrestrial magnetic field models may represent a useful approach to modelling the three-dimensional magnetic field at Saturn.Key words. Magnetospheric physics (current systems; magnetosphere-ionosphere interactions; solar wind-magnetosphere interactions)

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