Divergence and Vorticity of Solar Subsurface Flows Derived from Ring-Diagram Analysis of MDI and GONG Data

摘要: We measure the relation between divergence and vorticity of subsurface horizontal flows as a function unsigned surface magnetic flux. Observations from Michelson Doppler Imager (MDI) Dynamics Program Global Oscillation Network Group (GONG) have been analyzed with standard ring-diagram technique to depth about 16 Mm. study residual after subtracting large-scale trends (low-order polynomial fits in latitude) measured velocities. On average, quiet regions are characterized by weakly divergent small anticyclonic (clockwise northern hemisphere), while locations high activity show convergent combined cyclonic (counterclockwise hemisphere). Divergence anticorrelated (correlated) (southern) hemisphere. This is especially noticeable at greater depth, where nearly linear. These slight reversal highest levels flux; amplitude decreases flux levels, changes sign depths than 10 The product flows, proxy vertical contribution kinetic helicity density, on average negative (positive) values locations.