Title :
Helicity signatures in the dissipation range of solar wind turbulence
Author :
Howes, G.G. ; Quataert, E.
Author_Institution :
Univ. of Iowa, Iowa City, IA, USA
Abstract :
Measurements of small-scale turbulent fluctuations in the solar wind find a non-zero right-handed magnetic helicity. This has been interpreted as evidence for the importance of ion cyclotron damping. However, theoretical and empirical evidence suggests that the majority of the energy in solar wind turbulence resides in low frequency anisotropic kinetic Alfven wave fluctuations that are not subject to ion cyclotron damping. We demonstrate that a dissipation range comprised of kinetic Alfven waves also produces a net right-handed fluctuating magnetic helicity signature consistent with observations. Thus, the observed magnetic helicity signature does not imply that ion cyclotron damping is energetically important in the solar wind.
Keywords :
helicity (elementary particles); plasma Alfven waves; solar magnetism; solar wind; ion cyclotron damping; kinetic Alfven wave fluctuation; magnetic helicity signature; solar wind turbulence; Cities and towns; Cyclotrons; Damping; Fluctuations; Frequency; Kinetic theory; Magnetic anisotropy; Perpendicular magnetic anisotropy; USA Councils; Wind energy;
Conference_Titel :
Plasma Science - Abstracts, 2009. ICOPS 2009. IEEE International Conference on
Conference_Location :
San Diego, CA
Print_ISBN :
978-1-4244-2617-1
DOI :
10.1109/PLASMA.2009.5227739