Open AccessThe origin of long‐period Alfvén waves in the solar wind
Author(s) -
Zaqarashvili T. V.,
Belvedere G.
Publication year - 2005
Publication title -
monthly notices of the royal astronomical society: letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.067
H-Index - 122
eISSN - 1745-3933
pISSN - 1745-3925
DOI - 10.1111/j.1745-3933.2005.00069.x
Subject(s) - physics , solar wind , convection zone , convection , period (music) , geophysics , helioseismology , magnetic field , atmospheric sciences , astrophysics , mechanics , computational physics , acoustics , quantum mechanics
We suggest that the observed long‐period Alfvén waves in the solar wind may be generated in the solar interior as a result of the pulsation of the Sun in the fundamental radial mode. The period of this pulsation is about 1 h. The pulsation causes a periodic variation of density and large‐scale magnetic field, which affects the Alfvén speed in the solar interior. Consequently, Alfvén waves with half the frequency of pulsation (i.e. with double the period) can be parametrically amplified in the interior below the convection zone as a result of the recently suggested swing wave–wave interaction. Therefore the amplified Alfvén waves have periods of several hours. The waves can propagate upwards through the convection zone to the solar atmosphere and cause the observed long‐period Alfvén oscillations in the solar wind.