Abstract
This paper studies the problems of mathematical description of physical processes in open non-equilibrium atmosphere. It is proposed that the mathematical description should be based on the idea that properties of an open system are determined by the properties of its elements and external constraints. It is also explained why atmosphere should be represented by an open non-equilibrium system of gas and radiation. Difference between physical processes in the above mentioned system and equilibrium atmosphere is given. The modification of equations of non-equilibrium thermodynamics for a system of gas and radiation is proposed. Possible ways for further development of tools of non-equilibrium thermodynamics are considered.