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P: Plasmaphysik

P 21: Poster: Grundprobleme, Theorie, Plasmatechnologie, Astrophysikalische Plasmen

P 21.30: Poster

Montag, 18. März 2002, 17:40–18:40, HZO Foyer

Farley-Buneman type waves in the solar atmosphere — •Claudia-Veronika Meister¹, Victor Liperovsky², Elena Liperovskaya², Konstantin Popov², and Sergej Senchenkov² — ¹Space Plasma Physics, Potsdam, Germany — ²Institute of Physics of the Earth, Moscow, Russia

The possibility of the excitation of Farley-Buneman type waves in the solar atmosphere is examined. It is shown that the conditions for the generation of a Farley-Buneman type instability can be realized in the chromosphere of the Sun about 1000 km above the photosphere. But while the usual Farley-Buneman waves studied in relation to the Earth’s ionosphere are almost electrostatic, the Farley-Buneman type waves in the solar atmosphere are electromagnetic ones. A parameter ξ is found which increases with growing plasma density and ion-neutral collision frequencies, but decreases in case of stronger magnetic fields and larger wave numbers. If ξ<1 is satisfied, electromagnetic effects hinder the generation of Farley-Buneman type waves. In the contrary case ξ>1, the Farley-Buneman type waves are not excited at all. In weakly ionized solar regions, Farley-Buneman type waves might contribute to the energy dissipation of nonstationary streams of neutral gases. It is possible that Farley-Buneman type waves occur also in atmospheres of other stars besides the Sun.