Thermal processes can play an important role in dynamics, chemistry, and dust growth of protoplanetary disks. Using numerical hydrodynamics simulations in the thin-disk limit, we explore different approaches to computing the disk thermal structure: a simplified beta-cooling approach, in which the rate of disk cooling is proportional to the local dynamical time, a fiducial model with equal dust and gas temperatures calculated taking viscous heating, irradiation, and radiative
cooling into account, and also a more sophisticated approach allowing for decoupled dust and gas temperatures. We found that the gas temperature may significantly exceed that of dust in the outer regions of young protoplanetary disks. The outer envelope, however, shows an inverse trend with the gas temperatures dropping below that of dust. Models with a constant beta-parameter fail to reproduce the disk evolution with more sophisticated thermal schemes.
We discuss whether the temperature decoupling is important for the gas dynamics,
chemical evolution, and dust growth in young protoplanetary disks.