2014/07/22 by L. Del Zanna, L. Matteini, Lorenzo Matteini +5 · 2 citations
Biochemistry, Genetics and Molecular Biology · Physics and Astronomy · #Amplitude #Cascade #Computational physics #Convective instability #Excitation #Geomagnetism and Paleomagnetism Studies #Instability #Ionosphere and magnetosphere dynamics #Magnetic field #Magnetohydrodynamics #Mechanics #Monochromatic color #Oblique case #Optics #Physics #Solar and Space Plasma Dynamics #Solar wind #Transverse plane #Wave propagation #astro-ph.SR #physics.space-ph
paper · pdf · doi:10.1017/s0022377814000579
published as J. Plasma Phys. 81 (2015) 325810102 · 20 pages, 9 figures, accepted for publication in Joural of Plasma Physics
arxiv created 2014/07/22 · openalex publication_date 2014/08/19 · arxiv updated 2019/02/20 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The long-term evolution of large-amplitude Alfvén waves propagating in the solar wind is investigated by performing two-dimensional MHD simulations within the expanding box model. The linear and nonlinear phases of the parametric decay instability are studied for both circularly polarized waves in parallel propagation and for arc-polarized waves in oblique propagation. The non-monochromatic case is also considered. In the oblique case, the direct excitation of daughter modes transverse to the local background field is found for the first time in an expanding environment, and this transverse cascade seems to be favored for monochromatic mother waves. The expansion effect reduces the instability growth rate, and it can even suppress its onset for the lowest frequency modes considered here, possibly explaining the persistence of these outgoing waves in the solar wind.