ИСТИНА

Lowering of heavy element abundances Z according to modern determinations presents a problem of the solar modeling. We estimate settling rates of several heavy elements such as C, N, O, Ne, Si and Fe from the solar convective zone during evolution according to the Bahcall-Thoul technique. Acceleration of the heavy elements settling due to partial ionization and radiation-driven slowing are taken into account. Diffusion profile in modern Sun reveals a narrow region under the convective zone where heavy elements abundance remains almost the same due to specific effect of thermal diffusion. A rate of the elements settling from the convective zone depends on the convective zone depth and on the overshooting mixing around the low convective boundary. According to our results, diffusion settling is fairly small to explain entirely a low Z value in the photosphere.