2000/03/08 by R. Howe, J. Christensen‐Dalsgaard, J. Christensen-Dalsgaard +8 · 4 citations
Physics and Astronomy · #Astro and Planetary Science #Astronomy #Astrophysics #Convection #Convection zone #Doppler effect #Geology #Geometry #Geophysics #Mechanics #Physics #RADIUS #Rotation (mathematics) #Solar and Space Plasma Dynamics #Stellar, planetary, and galactic studies #Surface (topology) #astro-ph
paper · pdf · doi:10.1086/312623
4 pages, 4 figures To be published in ApJ Letters (accepted 3/3/2000)
arxiv created 2000/03/08 · openalex publication_date 2000/04/20 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Helioseismic observations have detected small temporal variations of the rotation rate below the solar surface that correspond to the so-called "torsional oscillations" known from Doppler measurements of the surface. These appear as bands of slower- and faster-than-average rotation moving equatorward. Here we establish, using complementary helioseismic observations over 4 yr from the GONG network and from the MDI instrument on board SOHO, that the banded flows are not merely a near-surface phenomenon: rather, they extend downward at least 60 Mm (some 8% of the total solar radius) and thus are evident over a significant fraction of the nearly 200 Mm depth of the solar convection zone.