This grant will continue the helioseismology program that is currently ongoing at California Institute of Technology and Big Bear Solar Observatory (BBSO). In the past several years many improvements have been made in methods for measuring solar p-mode oscillations, to the point where the BBSO measurements of p-mode frequencies, frequency splittings, linewidths, and amplitudes are among the best anywhere. These measurements have been used to better understand the excitation and dampening of the p-modes, to measure the solar rotation as a function of depth and latitude, and to infer other properties of the solar interior. This work will continue with the following scientific goals in mind: 1) to improve the measurement of the sun's internal rotation, from the deep core right up to the surface; 2) to continue monitoring the observed solar cycle variations in the p-mode frequency splittings, which are thought to arise from large-scale time-dependent temperature variations inside the sun; 3) to improve our understanding of the p-mode excitation and damping processes; and 4) to investigate the properties of the solar atmosphere using oscillations. The overall aim of this work is to use sophisticated helioseismology techniques to discern the internal dynamics of the sun. This in turn tells us about the 11 year variation. Clearly, this is important to solar terrestrial relations.
