Meridional flows from ring diagram analysis

Meridional circulation from the equator to the poles is found from ring diagram analysis of helioseismic data. The data. consist of SOI/MDI Dopplergrams taken every minute during its Dynamics Program in 1996. The time span used in this work is about 50 hours (similar to 3000 images). Studying 15-deg square sections centered at latitudes 0 degrees, +/-10 degrees, +/-15 degrees, +/-20 degrees, +/-30 degrees, +/-40 degrees, +/-50 degrees, and Carrington longitudes 90 degrees and 105 degrees, we find a remarkable behaviour in the meridional component of the horizontal velocity fields, with poleward flows between r/R-. = 0.97 and the surface. There is no evidence in this depth range of the return path of the meridional flows. The temporal stability of these flows is discussed in light of a synoptic map obtained using the same technique.