Wavelike Properties of Solar Supergranulation Detected in Doppler Shift Data

Abstract

Recently, Gizon, Duvall, & Schou suggested that supergranulation has a wavelike component. In this Letter, I show that the same phenomenon can be observed using surface Doppler shift data, thereby confirming their observations, which were made using a helioseismic time-distance technique. In addition to confirming those results, I show that the wave motion is predominantly longitudinal (the fluid displacement is in the direction of propagation), and I am able to extend the results for the rotation and the meridional flow beyond +/-70° latitude. The meridional flow results, which extend further than previous helioseismic measurements, appear to show no sign of a second cell.