2009/05/19 by Jr Duvall, Thomas L. Duvall, Jr, Shravan Hanasoge +3
Physics and Astronomy · #Astro and Planetary Science #FOS: Physical sciences #Instrumentation and Methods for Astrophysics (astro-ph.IM) #Solar and Space Plasma Dynamics #Solar and Stellar Astrophysics (astro-ph.SR) #Stellar, planetary, and galactic studies #astro-ph.IM #astro-ph.SR
paper · pdf · doi:10.48550/arxiv.0905.3132
7 Pages, 6 Figures, conference proceeding SOHO-GONG 2008
arxiv created 2009/05/19 · openalex publication_date 2009/05/19 · arxiv updated 2012/08/27 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Measuring the depth variation of the meridional flows is important for understanding the solar cycle, at least according to a number of dynamo models. While attempting to extend the early observations of \citetgilesthesis of time-distance measurements of flow, we have stumbled upon some systematic errors that can affect these measurements: 1) the additional distance traveled by radiation coming from points away from disk center causes an apparent `shrinking' Sun, that is an apparent flow towards the disk center and 2) in measurements away from the central longitude, the rotation signal can leak into meridional flow signals. Attempts to understand and overcome these systematic problems will be presented. Forward models based on ray theory have been applied in order to test the sensitivity of travel times to various models.