scholarly journals Low‐Energy (

2019 ◽  
Vol 124 (1) ◽  
pp. 405-419 ◽  
Author(s):  
Matina Gkioulidou ◽  
S. Ohtani ◽  
A. Y. Ukhorskiy ◽  
D. G. Mitchell ◽  
K. Takahashi ◽  
...  
Keyword(s):  
Low Energy ◽  
Ion Outflow ◽  
Inner Magnetosphere ◽  
Van Allen Probes

On the Low Energy (< keV) O+ Ion Outflow directly into the Inner Magnetosphere

2021 ◽  
Author(s):  
Matina Gkioulidou ◽  
Shin Ohtani ◽  
Don Mitchell ◽  
Harlan Spence
Keyword(s):  
Low Energy ◽  
Physical Processes ◽  
Crucial Issue ◽  
Ion Outflow ◽  
Inner Magnetosphere ◽  
Poynting Flux ◽  
Van Allen Probes ◽  
Radial Frequency ◽  
Hydromagnetic Waves ◽  
Open Question

&lt;p&gt;The development of low energy (&lt; keV) O+ ions in the inner magnetosphere is a crucial issue for various aspects of magnetospheric dynamics: i) Recent studies have suggested that low energy O+ can be locally accelerated to few keV energies inside geosynchronous orbit, and thus can constitute a significant source of the storm-time ring current O+ that could dominate the energy density during storms, ii) Mass loaded densities are important for accurate location of the plasmapause, which, in turn, is necessary for meaningful calculation of the field line resonance radial frequency profiles of ULF hydromagnetic waves in plasmasphere, iii) since O+ is only of ionospheric origin, its outflow from ionosphere into the magnetosphere is a manifestation of fundamental processes concerning energy and mass flow within the coupled Magnetosphere &amp;#8211; Ionosphere system. Although a lot of progress has been made on O+ outflow at high latitudes and its subsequent transport and acceleration within the magnetotail and plasma sheet, the source of low-energy O+ within the inner magnetosphere remains a compelling open question. The Helium Oxygen Proton and Electron (HOPE) mass spectrometer instrument aboard Van Allen Probes, which move in highly elliptical, low inclination orbits with apogee of 5.8 RE, has repeatedly detected field aligned flux enhancements of eV to hundreds of eV O+ ions, which indicate O+ outflow directly into the inner magnetosphere. We systematically investigate, throughout the duration of the Van Allen Probes mission (2012 &amp;#8211; 2019), the occurrence of such events with respect to L and MLT, the dependence of their directionality (bi-directional or unidirectional) and the lowest and highest energies involved on L, MLT and MLAT. We categorize the outflow events with respect to plasmapause location (when its determination is possible) and identify whether there is enhancement of O+ density. This categorization is important because if the outflows occur close to the plasmapause location, and depending on the density enhancement they cause, they could be responsible for the formation of O+ torus, whose source has been under debate for years. Finally, in order to identify the physical processes that lead to the ionospheric outflow, we also examine whether there are dipolarizations and/or enhancements of the field-aligned poynting flux associated with these outflow events.&lt;/p&gt;

scholarly journals Cluster observation of few-hour-scale evolution of structured plasma in the inner magnetosphere

2013 ◽  
Vol 31 (9) ◽  
pp. 1569-1578 ◽  
Author(s):  
M. Yamauchi ◽  
I. Dandouras ◽  
H. Rème ◽  
R. Lundin ◽  
L. M. Kistler
Keyword(s):  
Local Time ◽  
Trapped Ions ◽  
Low Energy ◽  
Local Times ◽  
Significant Enhancement ◽  
Occurrence Rate ◽  
Wide Energy Range ◽  
Inner Magnetosphere ◽  
Wide Energy ◽  
Cluster Ion

Abstract. Using Cluster Ion Spectrometry (CIS) data from the spacecraft-4 perigee traversals during the 2001–2006 period (nearly 500 traversals after removing those that are highly contaminated by radiation belt particles), we statistically examined the local time distribution of structured trapped ions at sub- to few-keV range as well as inbound–outbound differences of these ion signatures in intensities and energy–latitude dispersion directions. Since the Cluster orbit during this period was almost constant and approximately north–south symmetric at nearly constant local time near the perigee, inbound–outbound differences are attributed to temporal developments in a 1–2 h timescale. Three types of structured ions at sub- to few keV range that are commonly found in the inner magnetosphere are examined: – Energy–latitude dispersed structured ions at less than a few keV, – Short-lived dispersionless ion stripes at wide energy range extending 0.1–10 keV, – Short-lived low-energy ion bursts at less than a few hundred eV. The statistics revealed that the wedge-like dispersed ions are most often observed in the dawn sector (60% of traversals), and a large portion of them show significant enhancement during the traversals at all local times. The short-lived ion stripes are predominantly found near midnight, where most stripes are significantly enhanced during the traversals and are associated with substorm activities with geomagnetic AL < −300 nT. The low-energy bursts are observed at all local times and under all geomagnetic conditions, with moderate peak of the occurrence rate in the afternoon sector. A large portion of them again show significant enhancement or decay during the traversals.

scholarly journals Day-night asymmetries of low-energy electrons in Saturn's inner magnetosphere

2011 ◽  
Vol 38 (8) ◽  
pp. n/a-n/a ◽  
Author(s):  
A. D. DeJong ◽  
J. L. Burch ◽  
J. Goldstein ◽  
A. J. Coates ◽  
F. Crary
Keyword(s):  
Low Energy ◽  
Inner Magnetosphere ◽  
Low Energy Electrons

scholarly journals On the origin of low‐energy electrons in the inner magnetosphere: Fluxes and pitch‐angle distributions

2017 ◽  
Vol 122 (2) ◽  
pp. 1789-1802 ◽  
Author(s):  
M. H. Denton ◽  
G. D. Reeves ◽  
B. A. Larsen ◽  
R. H. W. Friedel ◽  
M. F. Thomsen ◽  
...  
Keyword(s):  
Pitch Angle ◽  
Low Energy ◽  
Inner Magnetosphere ◽  
Low Energy Electrons

Dispersive Alfvén Wave Control of O + Ion Outflow and Energy Densities in the Inner Magnetosphere

2019 ◽  
Vol 46 (15) ◽  
pp. 8597-8606 ◽  
Author(s):  
A. J. Hull ◽  
C. C. Chaston ◽  
J. W. Bonnell ◽  
J. R. Wygant ◽  
C. A. Kletzing ◽  
...  
Keyword(s):  
Alfven Wave ◽  
Ion Outflow ◽  
Inner Magnetosphere ◽  
Dispersive Alfvén Wave ◽  
Wave Control

scholarly journals Void structure of O+ ions in the inner magnetosphere observed by the Van Allen Probes

2016 ◽  
Vol 121 (12) ◽  
pp. 11,698-11,713 ◽  
Author(s):  
Y. Nakayama ◽  
Y. Ebihara ◽  
S. Ohtani ◽  
M. Gkioulidou ◽  
K. Takahashi ◽  
...  
Keyword(s):  
Inner Magnetosphere ◽  
Van Allen Probes ◽  
Void Structure

scholarly journals Empirical models of the low-energy plasma in the inner magnetosphere

Space Weather ◽  
2005 ◽  
Vol 3 (12) ◽  
pp. n/a-n/a ◽  
Author(s):  
J. L. Roeder ◽  
M. W. Chen ◽  
J. F. Fennell ◽  
R. Friedel
Keyword(s):  
Empirical Models ◽  
Low Energy ◽  
Inner Magnetosphere

Characteristics of Sudden Commencements Observed by Van Allen Probes in the Inner Magnetosphere

2018 ◽  
Vol 123 (2) ◽  
pp. 1295-1304
Author(s):  
A. Fathy ◽  
K.-H. Kim ◽  
J.-S. Park ◽  
H. Jin ◽  
C. Kletzing ◽  
...  
Keyword(s):  
Inner Magnetosphere ◽  
Van Allen Probes ◽  
Sudden Commencements

scholarly journals Low-energy electrons in Saturn's inner magnetosphere and their role in interchange injections

2010 ◽  
Vol 115 (A10) ◽  
pp. n/a-n/a ◽  
Author(s):  
A. D. DeJong ◽  
J. L. Burch ◽  
J. Goldstein ◽  
A. J. Coates ◽  
D. T. Young
Keyword(s):  
Low Energy ◽  
Inner Magnetosphere ◽  
Low Energy Electrons
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