Subsurface meridional flow speed shows an anti-correlation with the magnetic flux being transported poleward above the latitude of 35°. In the lower latitude, the residual meridional flow, after a long-time mean profile is subtracted, shows converging flow toward the activity belts.
Motivated by recent observations we have explored whether the flux-transport dynamo model can work with multi-cell meridional flow. We find that it can work when certain conditions are fulfilled.
Giant convection cells discovered with HMI Doppler data are found to transport angular momentum equatorward. This helps to resolve the 400-year old mystery of the Sun’s rapidly rotating equator.
Analysis of a large number of supergranules observed with HMI and simulations with a convectively stabilized solar model imply that the average supergranular cell has a peak upflow of 240 m s-1 at a depth of 2.3 Mm and a corresponding peak outward horizontal flow of 700 m s-1 at a depth of 1.6 Mm.
Solar meridional circulation, if mechanically driven and thermally
braked, contains two cells in latitude; generating two cells in depth,
recently observed by SDO/HMI, is a new challenge to theory.
Acoustic travel time reveals an equatorward meridional flow in the middle of the solar convection zone. Inversion reveals an evidence of double-cell meridional circulation inside the Sun.