An Average Supergranule: Much Larger Vertical Flows Than Expected

Supergranules are believed to be an evidence for large-scale subsurface convection. The vertical component of the supergranular flow field is very hard to measure, but it is considered only a few m/s in and below the photosphere. Here I present the results of the analysis using three-dimensional inversion for time-distance helioseismology that indicate existence of the large-magnitude vertical upflow in the near sub-surface layers. Possible issues and consequences of this inference are also discussed.