EDP Sciences
Free access
Volume 429, Number 3, January III 2005
Page(s) 1069 - 1080
Section The Sun
DOI http://dx.doi.org/10.1051/0004-6361:20041348

A&A 429, 1069-1080 (2005)
DOI: 10.1051/0004-6361:20041348

Solar cycle influence on the interaction of the solar wind with Local Interstellar Cloud

V. Izmodenov1, 2, Y. Malama2 and M. S. Ruderman3

1  Lomonosov Moscow State University, Department of Aeromechanics and Gas Dynamics, Faculty of Mechanics and Mathematics, and Institute of Mechanics, Moscow 119899, Russia
    e-mail: izmod@ipmnet.ru
2  Institute for Problems in Mechanics, Russian Academy of Sciences, Prospect Vernadskogo 101-1, Moscow 117526, Russia
3  Department of Applied Mathematics, University of Sheffield, Hicks Building, Hounsfield Road, Sheffield S3 7RH, UK

(Received 25 May 2004 / Accepted 3 September 2004)

We present results of a new time-dependent kinetic model of the H atom penetration through the solar wind - interstellar medium interaction region. A kinetic 6D (time, two dimensions in space, and three dimensions in velocity-space) equation for interstellar H atoms was solved self-consistently with time-dependent Euler equations for the solar wind and interstellar charged components. We study the response of the interaction region to 11-year solar cycle variations of the solar wind dynamic pressure. It is shown that the termination shock location varies within $\pm$7 AU, the heliopause variation is ~4 AU, and the bow shock variation is negligible. At large heliocentric distances, the solar cycle induces 10-12% fluctuations in the number density of both primary and secondary interstellar H atoms and atoms created in the inner heliosheath. We underline the kinetic behavior of the fluctuations of the H atom populations. Closer to the Sun the fluctuations increase up to 30-35% at 5 AU due to solar cycle variation of the charge exchange rate. Solar cycle variations of interstellar H atoms in the heliospheric interface and within the heliosphere may have major importance for the interpretation of H atom observations inside the heliosphere.

Key words: Sun: solar wind -- interplanetary medium -- ISM : atoms -- Sun: activity -- hydrodynamics

© ESO 2005