2015/04/02 by Benjamin J. Greer, Bradley W. Hindman, Nicholas A. Featherstone +1 · 83 citations
Biochemistry, Genetics and Molecular Biology · Physics and Astronomy · #Composite material #Convection #Geology #Geomagnetism and Paleomagnetism Studies #Geophysics #Ionosphere and magnetosphere dynamics #Layer (electronics) #Materials science #Mechanics #Optics #Petrology #Physics #Shear (geology) #Solar and Space Plasma Dynamics #Surface layer #astro-ph.SR
paper · pdf · doi:10.1088/2041-8205/803/2/l17
published in The Astrophysical Journal Letters 803(2), L17 (IOP Publishing) · 12 pages, 5 figures
arxiv created 2015/04/02 · openalex publication_date 2015/04/14 · arxiv updated 2015/04/16 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Using a new implementation of ring-diagram helioseismology, we ascertain the strength and spatial scale of convective flows throughout the near-surface shear layer. Our ring-diagram technique employs highly overlapped analysis regions and an efficient method of three-dimensional inversion to measure convective motions with a resolution that ranges from 3 Mm at the surface to 80 Mm at the base of the layer. We find the rms horizontal flow speed to peak at 427 m s −1 at the photosphere and fall to a minimum of 124 m s −1 between 20 and 30 Mm. From the velocity amplitude and the dominant horizontal scales seen at each depth, we infer the level of rotational influence on convection to be low near the surface, but transition to a significant level at the base of the near-surface shear layer with a Rossby number varying between 2.2 to as low as 0.1.