Modification of Proton Velocity Distributions by Alfvénic Turbulence in the Solar Wind

dc.contributor.author	Pierrard, V.
dc.contributor.author	Voitenko, Y.
dc.date	2013
dc.date.accessioned	2016-03-25T11:11:10Z
dc.date.available	2016-03-25T11:11:10Z
dc.identifier.uri	https://orfeo.belnet.be/handle/internal/2912
dc.description	In the present paper, the proton velocity distribution function (VDF) in the solar wind is determined by numerically solving the kinetic evolution equation. We compare the results obtained when considering the effects of external forces and Coulomb collisions with those obtained by adding effects of Alfvén wave turbulence. We use Fokker-Planck diffusion terms to calculate the Alfvénic turbulence, which take into account observed turbulence spectra and kinetic effects of the finite proton gyroradius. Assuming a displaced Maxwellian for the proton VDF at the simulation boundary at 14 solar radii, we show that the turbulence leads to a fast (within several solar radii) development of the anti-sunward tail in the proton VDF. Our results provide a natural explanation for the nonthermal tails in the proton VDFs, which are often observed in-situ in the solar wind beyond 0.3 AU.
dc.language	eng
dc.title	Modification of Proton Velocity Distributions by Alfvénic Turbulence in the Solar Wind
dc.type	Article
dc.subject.frascati	Physical sciences
dc.audience	Scientific
dc.source.title	Solar Physics
dc.source.volume	288
dc.source.issue	1
dc.source.page	355-368
Orfeo.peerreviewed	Yes
dc.identifier.doi	10.1007/s11207-013-0294-8
dc.identifier.scopus	2-s2.0-84886726735