Solar granulation and oscillations as spatially random processes

Using Sheeley and Bhatnagar's technique to separate the slowly varying and oscillatory component of the photospheric velocity field, we analyze high spatial resolution lambda6102.7 velocity grams (subtracted spectrohelio-grams). A new way of interpreting the power spectra is presented. By invoking simple random models of the velocity field, the shape of the power spectra and autocorrelation functions can be explained quantitatively, and the results show that there are no large cells in either field. The oscillations have a mean size of 6.9 inches, and the rms velocity amplitude is 0.42 km s-1. For the slowly varying component (granulation at disk center), we find V/sub rms/ = 0.24 km s-1. The effects of seeing are discussed. The interpretation of our results leads to the identification of a restricted region in the k/subx/-ω diagnostic diagram in which the oscillations fall