Hunting for Giant Cells at the Solar Poles

Abstract:

Our Sun’s magnetic field is built by dynamo action in its subphotospheric convection zone. That region spans the outer 30% of the star in radius. Most models of convection predict that the solar convection zone is filled with convective cells that reach from the near surface region all the way down to the bottom of the convection zone. These so-called “giant cells” of convection are surprisingly elusive and hard to find; the most convincing observations do not show them to exist in their theoretically-expected form. Our observations to date have been confined to the solar equatorial regions and the solar mid-latitudes; it turns out that this may be a particularly difficult region in which to detect the giant cells. Here we use modern simulations of global-scale convection and an understanding of rotationally-constrained fluid dynamics to argue that it might be much easier to detect signatures of the giant cells at the solar poles than at the solar equator.