Persistent Near-Surface Flow Structures from Local Helioseismology
Abstract
Near-surface flows measured by the ring-diagram technique of local helioseismology show structures that persist over multiple rotations. We examine these phenomena using data from the {\em Global Oscillation Network Group} (GONG) and the {\em Helioseismic and Magnetic Imager} (HMI) and show that a correlation analysis of the structures can be used to estimate the rotation rate as a function of latitude, giving a result consistent with the near-surface rate from global helioseismology and slightly slower than that obtained from a similar analysis of the surface magnetic field strength. At latitudes of 60 and above the HMI flow data reveal a strong signature of a two-sided zonal flow structure. This signature may be related to recent reports of "giant cells" in solar convection.
Cite
@article{arxiv.1507.06525,
title = {Persistent Near-Surface Flow Structures from Local Helioseismology},
author = {R. Howe and R. W. Komm and D. Baker and L. Harra and L. van Driel-Gesztelyi and R. S. Bogart},
journal= {arXiv preprint arXiv:1507.06525},
year = {2015}
}