PF-02-0037

A global view on the evolution of protoplanetary disks: dust, gas and chemical composition.

Uma Gorti

We investigate the effects of radial and vertical transport processes in disks on their chemical and physical structure. The new models consider XUV irradiation, grain surface chemistry and particle-gas dynamical interactions in a framework that solves for disk gas and dust evolution with time. The disk evolution is solved using standard 1D expressions for disk surface densities of gas and dust particles of various sizes as determined by collisional growth/fragmentation. Chemical species in the vapor phase and in the condensed phase (as ices on dust particles) are explicitly tracked as well, using a chemical network that is solved on a 2D structure (that evolves as determined by the 1D instantaneous surface densities). We consider an evolving gas disk background as the disk accretes onto the star and is finally dispersed. Mass loss due to winds is incorporated via a sink term and various planetesimal formation criteria (pebble growth, streaming instability) are also explored to examine any possible repercussions on disk physical/chemical evolution. Here, we present the first results from our new global chemo-dynamical disk models and discuss bulk chemical inventories as the disk evolves and gets dispersed in a few million years.