Wave-particle interactions near ΩHe+observed on board GEOS 1 and 2: 2. Generation of ion cyclotron waves and heating of He+ions

Modeling of pitch angle scattering of ring current protons at interaction with electromagnetic ion cyclotron waves during a nonstorm period was considered very seldom. Therefore it is used correlated observation of enhanced electromagnetic ion cyclotron (EMIC) waves and dynamic evolution of ring current proton flux collected by Cluster satellite near the location L = 4.5 during March 26–27, 2003, a nonstorm period (Dst > –10 nT). Energetic (5–30 keV) proton fluxes are found to drop rapidly (e.g., a half hour) at lower pitch angles, corresponding to intensified EMIC wave activities. As mathematical model is used the non-stationary one-dimensional pitch angle diffusion equation which allows to compute numerically density of phase space or pitch angle distribution of the charged particles in the Earth’s magnetosphere. The model depends on time t, a local pitch angle and several parameters (the mass of a particle, the energy, the McIlwain parameter, the magnetic local time or geomagnetic eastern longitude, the geomagnetic activity index, parameter of the charged particle pitch angle distribution taken for the 90 degrees pitch angle at t = 0, the lifetime due to wave–particle interactions). This model allows numerically to estimate also for different geophysical conditions a lifetime due to wave–particle interactions. It is shown, that EMIC waves can yield decrements in proton flux within 30 minutes, consistent with the observational data. The good consent is received. Comparison of results on full model for the pitch angle range from 0 up to 180 degrees and on the model for the 90 degrees pitch angle is lead. For a perpendicular differential flux of the Earth’s ring current protons very good consent with the maximal relative error approximately 3.23 % is received

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Properties of A Supercritical Quasi-Perpendicular Interplanetary Shock Propagating in Super-Alfvénic Solar Wind: from MHD to Kinetic Scales

10.5194/egusphere-egu21-4908 ◽

2021 ◽

Author(s):

Mingzhe Liu ◽

Zhongwei Yang ◽

Ying D. Liu ◽

Bertrand Lembege ◽

Karine Issautier ◽

...

Keyword(s):

Solar Wind ◽

Energy Dissipation ◽

Interplanetary Shock ◽

Particle Interactions ◽

Temperature Anisotropy ◽

Ion Cyclotron Waves ◽

Proton Temperature ◽

Ion Cyclotron ◽

Mirror Mode

We investigate the properties of an interplanetary shock (MA=3.0, &#952;Bn=80&#176;) propagating in Super-Alfv&#233;nic solar wind observed on September 12th, 1999 with in situ Wind/MFI and Wind/3DP observations. Key results are obtained concerning the possible energy dissipation mechanisms across the shock and how the shock modifies the ambient solar wind at MHD and kinetic scales:&#160; (1) Waves observed in the far upstream of the shock are incompressional and mostly shear Alfv&#233;n waves.&#160; (2) In the downstream, the shocked solar wind shows both Alfv&#233;nic and mirror-mode features due to the coupling between the Alfv&#233;n waves and ion mirror-mode waves.&#160; (3) Specularly reflected gyrating ions, whistler waves, and ion cyclotron waves are observed around the shock ramp, indicating that the shock may rely on both particle reflection and wave-particle interactions for energy dissipation.&#160; (4) Both ion cyclotron and mirror mode instabilities may be excited in the downstream of the shock since the proton temperature anisotropy touches their thresholds due to the enhanced proton temperature anisotropy.&#160; (5) Whistler heat flux instabilities excited around the shock give free energy for the whistler precursors, which help explain the isotropic electron number and energy flux together with the normal betatron acceleration of electrons across the shock.&#160; (6) The shock may be somehow connected to the electron foreshock region of the Earth&#8217;s bow shock, since Bx > 0, By < 0, and the electron flux varies only when the electron pitch angles are less than PA = 90&#176;, which should be further investigated. Furthermore, the interaction between Alfv&#233;n waves and the shock and how the shock modifies the properties of the Alfv&#233;n waves are also discussed.

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Wave‐Particle Interactions Associated With Io's Auroral Footprint: Evidence of Alfvén, Ion Cyclotron, and Whistler Modes

Geophysical Research Letters ◽

10.1029/2020gl088432 ◽

2020 ◽

Vol 47 (22) ◽

Cited By ~ 3

Author(s):

A. H. Sulaiman ◽

G. B. Hospodarsky ◽

S. S. Elliott ◽

W. S. Kurth ◽

D. A. Gurnett ◽

...

Keyword(s):

Particle Interactions ◽

Ion Cyclotron ◽

Wave Particle Interactions

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Dissipation and wave-ion interaction in the solar wind: Links between fluid and kinetic theory

Nonlinear Processes in Geophysics ◽

10.5194/npg-6-149-1999 ◽

1999 ◽

Vol 6 (3/4) ◽

pp. 149-160 ◽

Cited By ~ 18

Author(s):

E. Marsch

Keyword(s):

Magnetic Field ◽

Solar Wind ◽

Wave Spectrum ◽

Type Model ◽

Particle Interactions ◽

Quasilinear Theory ◽

Ion Cyclotron Waves ◽

Polarized Waves ◽

Left And Right ◽

Wave Particle Interactions

Abstract. In this paper we establish links between turbulence dissipation and wave-particle interactions in the solar corona and wind. Based on quasilinear theory, a set of anisotropic, multi-component fluid equations is derived, which describe the wave-particle interactions of ions with Alfvén waves and ion-cyclotron waves or magnetosonic waves propagating along the mean magnetic field. The associated equations for the wave spectrum and the heating and acceleration of the ions are derived. In fast solar wind streams heavy ions have about equal thermal speeds as the protons and flow faster than them. In order to explain the observed relations, Tj / Tp ≈ mj /mp and Uj Up ≈ VA, a numerical fluid-type model is developed, which takes into account the relevant wave-particle interactions. It is shown that left- and right-handed polarized waves propagating away from the Sun parallel to the interplanetary magnetic field can resonantly heat and accelerate minor ions preferentially with respect to the protons in close agreement with the measured characteristics of ion velocity distributions. Finally, some results from a simple analytical model are discussed.

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Feasibility of Ion-cyclotron Resonant Heating in the Solar Wind

10.5194/egusphere-egu21-6858 ◽

2021 ◽

Author(s):

Roberto E. Navarro ◽

Victor Muñoz ◽

Juan A. Valdivia ◽

Pablo S. Moya

Keyword(s):

Solar Wind ◽

Solar Wind Plasma ◽

Alpha Particles ◽

Particle Interactions ◽

Fermi Acceleration ◽

Ion Cyclotron Waves ◽

Proton Temperature ◽

Propagating Waves ◽

Ion Cyclotron ◽

Cold Electrons

Wave-particle interactions are believed to be one of the most important kinetic processes regulating the heating and acceleration of Solar Wind plasma. One possible explanation to the observed preferential heating of alpha (He+2) ions relies on a process similar to a second order Fermi acceleration mechanism. In this model, heavy ions are able to resonate with multiple counter-propagating ion-cyclotron waves, while protons can encounter only single resonances, resulting in the subsequent preferential energization of minor ions. In this work, we address and test this idea by calculating the number of plasma particles that are resonating with ion-cyclotron waves propagating parallel and anti-parallel to an ambient magnetic field in a proton/alpha plasma with cold electrons. Resonances are calculated through the proper kinetic multi-species dispersion relation of Alfven waves. We show that 100% of the alpha population can resonate with counter-propagating waves below a threshold &#916;U&#945;p/vA<U0+a(&#946;+&#946;0)b in the differential streaming between protons and alpha particles, where U0=-0.532, a=1.211, &#946;0=0.0275, and b=0.348 for isotropic ions. This threshold seems to match with constraints of the observed &#916;U&#945;p in the Solar Wind for low values of the proton plasma beta. Finally, it is also shown that this process is limited by the growth of plasma kinetic instabilities, a constraint that could explain alpha-to-proton temperature ratio observations in the Solar Wind at 1 AU.

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