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Abstract

Meridional circulation and differential rotation represent the radial, latitudinal, and longitudinal components of the global-scale axisymmetric flow field in the Sun; they are essential ingredients of dynamo models. Large-scale non-axisymmetric flows include the inertial mode oscillations (where the Coriolis effect is the restoring force) which dominate the temporal variations on the time scale of solar rotation period. The characteristics of inertial modes are sensitive to the physical conditions in the deep convection zone. Such large-scale flows can be detected from the horizontal flow field in the photosphere, measured by tracking the motion of granules or small magnetic features, or directly from the line-of-sight Doppler signal. Subsurface flows can be measured using helioseismic methods, such as time-distance or ring-diagram techniques. This talk will cover recent progress in and challenges of characterizing large-scale flows in the solar convection zone, and how these measurements may help constrain dynamo theories.