Abstract
A self-consistent picture of the atmospheres of T Tauri stars based on the solar analogy is gradually emerging. Theoretical models for the strueture of these atmospheres indicate that they can be deseribed in terms of a photosphere with a temperature rise above it, similar to the chromospheres found in the sun and other late-type stars, although with higher densities. In addition, the derived temperature profiles and the resulting fluxes, both in lines and in eontinua, are consistent with early and recent claims that the observed activity is produced by flares, spots and related type of surface inhomogeneities, as it is the case for other active stars. I review these indications, and explore in a preliminary way the energy requirements in the resulting atmospheres -
