Relationship between Horizontal Flow Velocity and Cell Lifetime for Supergranulation

Abstract

A study of 50 supergranular cells obtained from SOHO Dopplergrams was undertaken in order to investigate the relationship between the lifetime ($T$) and the horizontal flow velocity ($v_h$) of the cells. For this sample we find that the two parameters are correlated with a relation $v_h\propto T^{0.5}$ and $T$ is identified with the eddy turn-over time. This is in agreement with the turbulent convective model of the solar atmosphere where the velocity spectrum of supergranular field given by '$v_h \propto L^{1/3}$' can be identified with the Kolmogorov spectrum for the eddy size $L$.