Session 18 - The Sun.
Display session, Monday, January 13
Metropolitan Ballroom,

## [18.01] Testing the Structure of the Solar Superadiabatic Layer with Seismology

P. Demarque (Yale U.), D. B. Guenther (Saint Mary's U.), Y. -C. Kim (Yale U.)

Kim et al.(1995 ApJ,442,422;1996 ApJ,461,499) have recently carried out 3D numerical simulations of shallow convection in the Sun. These calculations, which apply to the transition from the inner part of the superadiabatic peak into the deeper adiabatic layers of the convection zone, treat the coupling of radiative and convective transport and include realistic physics in the solar model. Radiative transfer is treated in the diffusion approximation. The simulations show that the conventional mixing length formalism underestimates the ratio of radiative to convective transport in the outer layers of the solar convection zone. This effect has been simulated in the solar models by calculating the temperature gradient within the mixing length framework, adopting a variable mixing length parameter \alpha. We have constructed standard solar models precisely tuned to the Sun, using a simple linear dependence of \alpha on depth in the outer part of the solar convection zone. We show that increasing \alpha with depth in this way modifies the structure of the superadiabatic layer in the direction of improving agreement between the calculated and observed solar p-mode frequencies.