INFLUENCE OF A VARIABLE MIXING-LENGTH ON THE SOLAR P-MODE SPECTRUM

Using the usual formulation of the mixing-length theory, we have compu ted solar models with a ratio of the mixing-length to the pressure sca le height which varies with the position in the convective envelope. S everal functions for that variation have been tested. We find that sev eral of them produce significant improvement of the theoretical freque ncies at high orders. The models have also been compared with the seis mic model of Dziembowski et al. (1994) and with a function obtained th rough inversion by Vorontsov et al. (1994). These comparisons have sug gested two modifications in the physics of the models which improve th e fit with observations.