Stuttgart 2012 – scientific programme

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SYGP: Symposium Gemeinsame Probleme in Fusions- und astrophysikalischen Plasmen

SYGP 2: Posters

SYGP 2.4: Poster

Monday, March 12, 2012, 16:00–16:30, Poster.V

On solar wind ion kinetics in correlation with short-wavelength transverse waves — Sofiane Bourouaine and •Eckart Marsch — Max-Planck-Institut für Sonnensystemforschung, 37191 Katlenburg-Lindau

We present new results from a study with Helios data of the correlations between the temperature anisotropies of solar wind protons and alpha-particles and their differential streaming and the average power of waves at short wavelengths (about 10 to 100 proton inertial lengths). We find that both the normalized differential ion speed as well as the proton temperature anisotropy increase with growing relative wave power. Moreover, as long as the normalized (to the Alfven speed) differential speed stays below 0.5, the alpha-particle temperature anisotropy also correlates positively with the mean relative amplitude of the transverse fluctuations. In addition we obtain that the alpha-to-proton temperature ratio anti-correlates with the helium ion abundance. All these findings appear to be consistent with expectations from kinetic theory for the resonant interaction of the ions with Alfvén/ion-cyclotron waves, and for the resulting wave dissipation.