HR: 0800h
AN: SH21A-0287    [Abstracts]
TI: The evolution of the solar wind proton temperature anisotropy from 0.3 to 2.5 AU
AU: Matteini, L
EM: matteini@arcetri.astro.it
AF: Dipartimento di Astronomia e Scienza dello Spazio, Universita' degli Studi di Firenze, Largo Enrico Fermi, 2, Firenze, 50125, Italy
AU: Matteini, L
EM: matteini@arcetri.astro.it
AF: Lesia, Observatoire de Paris, 5, place Jules Janssen, Meudon, 92125, France
AU: * Hellinger, P
EM: Petr.Hellinger@ufa.cas.cz
AF: Institute of Atmospheric Physics, The Academy of Sciences of Czech Republic, Bocni II/1401, Prague, 14131, Czech Republic
AU: Landi, S
EM: slandi@arcetri.astro.it
AF: Dipartimento di Astronomia e Scienza dello Spazio, Universita' degli Studi di Firenze, Largo Enrico Fermi, 2, Firenze, 50125, Italy
AU: Pantellini, F
EM: filippo.pantellini@obspm.fr
AF: Lesia, Observatoire de Paris, 5, place Jules Janssen, Meudon, 92125, France
AU: Maksimovic, M
EM: milan.maksimovic@obspm.fr
AF: Lesia, Observatoire de Paris, 5, place Jules Janssen, Meudon, 92125, France
AU: Velli, M
EM: velli@arcetri.astro.it
AF: Dipartimento di Astronomia e Scienza dello Spazio, Universita' degli Studi di Firenze, Largo Enrico Fermi, 2, Firenze, 50125, Italy
AU: Velli, M
EM: velli@arcetri.astro.it
AF: Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109, United States
AU: Goldstein, B E
EM: Bruce.E.Goldstein@jpl.nasa.gov
AF: Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109, United States
AU: Marsch, E
EM: marsch@mps.mpg.de
AF: Max-Planck-Institut fur Sonnensystemforschung, Max-Planck-Strasse 2, Katlenburg-Lindau, D-37191, Germany
AB: We report an analysis of the proton temperature anisotropy evolution from 0.3 to 2.5 AU based on the Helios and Ulysses observations. With increasing distance, the fast wind data show a path in the parameter space (β_{\parallel p},T_{\perp p}/T_{\parallel p}), and the first part of the trajectory is well described by an anticorrelation between the temperature anisotropy T_{\perp p}/T_{\parallel p} and the proton parallel beta, while after 1 AU the evolution with distance in the parameter space changes and the data result in agreement with the constraints derived by a fire hose instability. The slow wind data show a more irregular behavior, and in general it is not possible to recover a single evolution path. However, on small temporal scale we find that different slow streams populate different regions of the parameter space, and this suggests that when considering single streams also the slow wind follows some possible evolution path.
DE: 2164 Solar wind plasma
DE: 7829 Kinetic waves and instabilities
DE: 7867 Wave/particle interactions (2483, 6984)
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2007 Fall Meeting