Non-homogeneous solar models with metal enriched envelopes

Solar models with enhancement of heavy elements in the convective envelopes are investigated using the updated input physics. Unlike previous low-Z models that adopt quite low central metal abundance to considerably reduce neutrino fluxes, we investigate the effects of moderate enrichment of heavy elements in the solar convection zone on the solar structure and p-mode oscillations. It is found that the metal enriched models have less massive convection zones with deeper bottom boundaries, and their temperature profiles are systematically lower while the sound speed profiles are higher in the interior and lower in the envelope than that of the standard model. The contamination of heavy elements at different evolution phases is investigated, which results in little influence on the properties of the solar age models. The surface helium abundance is reduced considerably, and is able to approach the seismically determined value when the enhancement of heavy elements in the convection zone is carefully adjusted. The p-mode frequency patterns of our metal enriched models are systematically 10 μHz lower than those of the standard model, and are in better agreement with the results of observations.