Local Helioseismology and Correlation Tracking Analysis of Surface Structures in Realistic Simulations of Solar Convection

We apply time-distance helioseismology, local correlation tracking andFourier spatial-temporal filtering methods to realistic supergranule scalesimulations of solar convection and compare the results with high-resolutionobservations from the SOHO Michelson Doppler Imager (MDI). Our objective is toinvestigate the surface and sub-surface convective structures and testhelioseismic measurements. The size and grid of the computational domain aresufficient to resolve various convective scales from granulation tosupergranulation. The spatial velocity spectrum is approximately a power lawfor scales larger than granules, with a continuous decrease in velocityamplitude with increasing size. Aside from granulation no special scales exist,although a small enhancement in power at supergranulation scales can be seen.We calculate the time-distance diagram for f- and p-modes and show that it isconsistent with the SOHO/MDI observations. From the simulation data wecalculate travel time maps for surface gravity waves (f-mode). We also applycorrelation tracking to the simulated vertical velocity in the photosphere tocalculate the corresponding horizontal flows. We compare both of these to theactual large-scale (filtered) simulation velocities. All three methods revealsimilar large scale convective patterns and provide an initial test oftime-distance methods.Comment: 15 pages, 9 figures (.ps format); accepted to ApJ (tentatively scheduled to appear in March 10, 2007 n2 issue); included files ms.bbl, aabib.bst, aabib.sty, aastex.cl