Ring current instabilities excited by the energetic oxygen ions

A. P. Kakad; S. V. Singh; G. S. Lakhina

doi:10.1063/1.2777117

Quasielectrostatic instabilities excited by energetic oxygen ions in the ring current region

Physics of Plasmas ◽

10.1063/1.1828465 ◽

2005 ◽

Vol 12 (1) ◽

pp. 012903 ◽

Cited By ~ 2

Author(s):

S. V. Singh ◽

A. P. Kakad ◽

G. S. Lakhina

Keyword(s):

Ring Current ◽

Oxygen Ions ◽

Current Region

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Tracking the Differential Transport and Acceleration of Nitrogen and Oxygen Ions from the Terrestrial Ionosphere to the Inner Magnetosphere

10.5194/egusphere-egu2020-10158 ◽

2020 ◽

Author(s):

Raluca Ilie ◽

Mei-Yun Lin ◽

Alex Glocer ◽

Muhammad Fraz Bashir

Keyword(s):

Ring Current ◽

High Energy ◽

Transport Processes ◽

Hot Electron ◽

Polar Wind ◽

Inner Magnetosphere ◽

Oxygen Ions ◽

Terrestrial Magnetosphere ◽

Nitrogen Ions ◽

Ion Species

The presence of heavy ions has a profound impact on the temporal response of the magnetosphere to internal and external forcing, and plays a key role in plasma entry and transport processes within the terrestrial magnetosphere.Numerous studies focused on the transport and energization of O+ through the ionosphere-magnetosphere system; however, relatively few have considered the contribution of N+ to the near-Earth plasma, even though past observations have established that N+ is a significant ion species in the ionosphere and its presence in the magnetosphere is significant. In spite of only 12% mass difference, N+ and O+ have different ionization potentials, scale heights and charge exchange cross sections. The latter, together with the geocoronal density distribution, plays a significant role in the formation of ENAs, which in turn controls the energy budget of the inner magnetosphere, and the overall loss of the ring current. Therefore, the outflow of N+ from the ionosphere, in addition to that of O+, affects the global structure and properties of the current sheet, the mass loading of the magnetosphere, and it leads to changes in the local properties of the plasma, which in turn can influence waves propagation.&#160;This study involves an integrated computational view of geospace, that solves and tracks the evolution of all relevant ion species, to systematically assess their regional and global influence on the various loss and acceleration mechanisms operating throughout the terrestrial magnetosphere. We employ the newly developed Seven Ion Polar Wind Outflow Model (7iPWOM), which in addition to tracking the transport of H+, He+ and O+, now solves for the heating and transport of N+, N2+, NO+ and O2+ in Earth&#8217;s polar wind. The 7iPWOM is coupled with a two-stream model of superthermal electrons (GLobal airglow, or GLOW) to account for the attenuated radiation, electron beam energy dissipation, and secondary electron impact. We show that during various solar conditions, the polar wind outflow solution using 7iPWOM improves significantly when compared with OGO observations.&#160;In addition, numerical simulations using the kinetic drift Hot Electron Ions Drift Integrator (HEIDI) model suggest that the contribution of outflowing N+ to the ring current dynamics is significant, as the presence of N+alters the development and the decay rate of the ring current. Electron transfer collisions are far more efficient at removing N+ the system, compared with the removal of O+ ions. Synthetic TWINS-like mass separated ENA images show that the presence on nitrogen ions in the ring current, even in small amounts, significantly alters the ENA fluxes, and the peak of oxygen ENA fluxes can vary for up to an order of magnitude, depending on the magnetosphere composition. These findings can explain recent observations of faster than expected decay of high energy oxygen ions, as measured by the RBSPICE instrument on board of the Van Allen Probe spacecraft. We speculate that the abundance of oxygen has been mis-estimated, as it is likely that some of the oxygen measurements to actually be include comparable abundances of nitrogen ions.

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Ring current oxygen ions escaping into the magnetosheath

Journal of Geophysical Research Atmospheres ◽

10.1029/2000ja000127 ◽

2001 ◽

Vol 106 (A11) ◽

pp. 25541-25556 ◽

Cited By ~ 44

Author(s):

Q.-G. Zong ◽

B. Wilken ◽

S. Y. Fu ◽

T. A. Fritz ◽

A. Korth ◽

...

Keyword(s):

Ring Current ◽

Oxygen Ions

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Role of helicon modes in the injection of oxygen ions in the ring current

Journal of Atmospheric and Solar-Terrestrial Physics ◽

10.1016/s1364-6826(00)00160-7 ◽

2001 ◽

Vol 63 (5) ◽

pp. 481-487 ◽

Cited By ~ 4

Author(s):

Gurbax S. Lakhina

Keyword(s):

Ring Current ◽

Oxygen Ions

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The role of ULF waves interacting with oxygen ions at the outer ring current during storm times

Journal of Geophysical Research Atmospheres ◽

10.1029/2010ja015683 ◽

2011 ◽

Vol 116 (A1) ◽

pp. n/a-n/a ◽

Cited By ~ 19

Author(s):

B. Yang ◽

Q.-G. Zong ◽

S. Y. Fu ◽

X. Li ◽

A. Korth ◽

...

Keyword(s):

Ring Current ◽

Outer Ring ◽

Ulf Waves ◽

Oxygen Ions

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Earth’s magnetotail as the reservoir of accelerated single- and multicharged oxygen ions replenishing radiation belts

10.5194/egusphere-egu2020-8520 ◽

2020 ◽

Author(s):

Elena Parkhomenko ◽

Vladimir Kalegaev ◽

Helmi Malova ◽

Mikhail Panasyuk ◽

Victor Popov ◽

...

Keyword(s):

Numerical Model ◽

Time Scale ◽

Large Scale ◽

Radiation Belt ◽

Ring Current ◽

Outer Region ◽

Radiation Belts ◽

Proton Radiation ◽

Oxygen Ions ◽

Oxygen Ion

In this work we are studying multicharged oxygen ion acceleration during substorms in the Earth's magnetotail as the source of ring current replenishment by energetic ion population. We used measurements obtained by the CRRES spacecraft for the comparison of experimental spectra of oxygen charge state in the outer region of the ring current and proton radiation belt with model results. We present a numerical model that allows to evaluate acceleration of oxygen ions O+-O+8 in the course of two possible perturbation processes: A) passage of multiple dipolarization fronts in the magnetotail; B) passage of fronts followed by electromagnetic turbulence. It is shown that acceleration processes depend on particle charges and time scale of electric field variations. Oxygen ions O+8 with average initial energies 12 keV are accelerated efficiently during multiple dipolarization processes of type (A) and their energies increased up to 7.4 MeV, whereas ions O+1 with the same energies were energized up to 1.9 &#1052;eV. It is shown that oxygen ions O+-O+2 are able to penetrate into the ring/radiation belts region with L between L=4.5 and L=7.5 in the process of plasma transfer on dipolarization fronts. For oxygen O+-O+8 the additional acceleration mechanism is required, such as large-scale electromagnetic turbulence, when the ions can get energies comparable with experimentally observed ones in the indicated range of L shell values. It is shown that the taking into account electromagnetic fluctuations, accompanying magnetic dipolarization, may explain the appearance of oxygen ion flows with energies greater than 3MeV in the near- Earth&#8217;s space.

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Ring current decay during storm recover phase: RBSP Observation

10.5194/egusphere-egu2020-21672 ◽

2020 ◽

Author(s):

Ao Chen ◽

Chao Yue ◽

Hongfei Chen ◽

Qiugang Zong

Keyword(s):

Charge Exchange ◽

Ring Current ◽

Current System ◽

Charged Particles ◽

Oxygen Ions ◽

Current Decay ◽

The Earth ◽

Comparison Results ◽

Wide Energy ◽

Fitting In

Ring curent is an important current system in the Earth's magnetosphere. Many charged particles, especially protons and oxygen ions, move around the Earth due to due to electromagnetic drifts, which forms the ring current. During the main phase of a magnetic storm, ring current will grow stronger while it will decay slowly during recover phase. It is thought that charge exchange is the main mechanism of ring current decay [Daglis et al., 1999]. Hereby we use charge exchange theories to calculate charge exchange lifetimes of protons and oxygen ions during recover phase of many storms. Meanwhile, data of RBSP has been used for fitting in order to get real lifetimes of &#160;protons and oxygen ions. We compared the observed lifetimes with the theory prediction and find that &#160;a. the two are close at high L(>4) values and low energy(<55keV) for protons, b. the two are similar in a wide energy(1~600keV) range but a relatively narrow L(different at different energies) range, c. day or night make little difference on the comparison results.

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