2010/01/06 by Laurent Gizon, L. Gizon, A. C. Birch +3 · 7 citations
Physics and Astronomy · #Convection #Convection zone #Helioseismology #Ionosphere and magnetosphere dynamics #Latitude #Meridional flow #Oscillation (cell signaling) #Solar and Space Plasma Dynamics #Solar cycle #Solar physics #Stellar, planetary, and galactic studies #Sunspot #astro-ph.SR
paper · pdf · doi:10.1146/annurev-astro-082708-101722
70 pages, 26 figures, submitted to Ann. Rev. Astron. Astrophys
arxiv created 2010/01/06 · openalex publication_date 2010/08/01 · arxiv updated 2015/05/14 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The Sun supports a rich spectrum of internal waves that are continuously excited by turbulent convection. The Global Oscillation Network Group (GONG) network and the SOHO/MDI (Solar and Heliospheric Observatory/Michelson Doppler Imager) space instrument provide an exceptional database of spatially resolved observations of solar oscillations, covering more than an entire sunspot cycle (11 years). Local helioseismology is a set of tools for probing the solar interior in three dimensions using measurements of wave travel times and local mode frequencies. Local helioseismology has discovered (a) near-surface vector flows associated with convection, (b) 250 m s −1 subsurface horizontal outflows around sunspots, (c) ∼50 m s −1 extended horizontal flows around active regions (converging near the surface and diverging below), (d) the effect of the Coriolis force on convective flows and active region flows, (e) the subsurface signature of the 15 m s −1 poleward meridional flow, (f) a ±5 m s −1 time-varying depth-dependent component of the meridional circulation around the mean latitude of activity, and (g) magnetic activity on the farside of the Sun.