SOME EVIDENCE FOR LARGE-SCALE MOTIONS ON THE SUN

The importance of two indicators, the energy density and the Blue wing/Red wing ratio of the rms wavelength shift, related to the mechanical energy flux of the 5-minutes oscillations, is investigated. The goal is to search for the existence of large-scale motions in the solar convective region. Results obtained by analysing high-spectral-resolution line profiles (5434.5 Fe I), obtained over a large spatial area, spanning a solar radius, are also discussed. We obtained horizontal spatial sequences for both indicators at three different heights in the solar photosphere (50 Km, 150 Km and 200 Km), which correspond to regions where the variations of the mechanical energy flux are larger. The spatial power spectra of these indicators clearly show the existence of a peak at approximately 200 Mm. The physical identification of this peak, and its relationship to the interaction between steady waves and large-scale velocity pattern in the solar convective region are discussed. Finally, the effect of magnetic features in our data set is briefly clarified.