Structure of solar granulation. II. Models of vertical motion

Several models proposed for the height dependence of the vertical motion associated with granules are used to compute photospheric line shifts. These predicted line shifts are compared with recent observations of line shifts resulting from granular motion in a number of lines whose heights of formation span the photosphere and low chromosphere. An empirical model of the granular flow giving agreement between predicted and observed line shifts is deduced. At a height 100 km above tauA=1 the amplitude of the granular flow is aproximately 2 km s-1, and an appropriate scale height for the granular flow at this altitude is approx.80 km