Temporal Variations

Mode parameters frequency (top), mode width (middle) and mode energy (bottom) show a marked solar-cycle variation. In the GONG analysis, the parameters are evaluated separately for each (l,m,n) mode. This allows us to use the m-dependence of the results to study latitudinal effects. Here, the changes for modes with 40 lte l lt 80 and 9 lte n lte 11 have been localized in latitude using an Optimally Localized Averages technique. The units are microhertz, microhertz, and 1030 erg, respectively. The increased frequency, increased linewidth and decreased energy of the modes correspond to the spatial distribution of magnetic flux.
Inverting rotational splittings allows us to study the differential rotation within the solar interior. Here, we show the deviation from a smooth profile for GONG (top) and MDI (middle) near the surface, and for MDI also at 0.93RSun The equatorward-migrating banded flows correspond to the 'torsional oscillation' and penetrate to at least 0.92RSun.

Rotation Movies


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