Diagnostics of Subphotospheric Sources of Solar Variability

Local helioseismology provides new tools for studying subphotospheric processes that are related to solar variability of various spatial and temporal scales. Large-scale flow patterns beneath active regions and sunspots affect the solar energy transport in the upper convection zone. Smaller-scale shearing and twisting flows may trigger instabilities of magnetic configurations that lead to flares and CMEs. We discuss the recent progress in the local helioseismology diagnostic tools and in our understanding of the subphotospheric dynamics and sources of variability.