Ring-diagram analysis of high-resolution MDI Dopplergrams

R. S. Bogart1, S. Basu2, D. A. Haber3 and J. Schou1

1Stanford University
2Yale University


Most local-area ring-diagram analysis to date has been performed on data at a surface spatial resolution of 1.4 Mm/pixel or worse. Continuous sets of Doppler data at higher resolution, up to 0.5 Mm/pixel, have been obtained by MDI during several campaigns lasting a day or longer over the course of the last five years. These data may provide important additional information about small-scale flows and structure variations in the immediate vicinity of the photosphere. Here we report on initial results of our analysis of selected small regions from these data sets.