This proposal concerns theoretical and observational studies of the effect of large-scale convection on helioseismic oscillations. Over the past few years this work has concentrated on solving the forward problem for the effect of convection on heliosesmic oscillations and on performing numerical simulations to determine the observable signature of giant-cells. The theoretical work will concentrate on four areas: (1) investigating the numerical application of quasi-degenerate perturbation theory so that the PI can model the heliosesmic effect of poloidal flows such as banana cells, (2) improving the numerical simulations with particular emphasis on developing a more realistic simulation of the source time history, (3) attempting to produce an approximate theory that governs nonstationary flows, and (4) investigating the application of asymptotic, ray theoretic, and scattering theories in the hope of illuminating the inverse problem. The recently initiated collaboration with Dr. Brown will concentrate first on developing robust methods by which individual apparent-m modal line-width measurements can be made. The technique will be optimized to extract the characteristic signature of giant-cells.
