Atmospheric Thermodynamics

Abstract

Thermodynamics represents a branch of physics which deals with the energy and work of the system and the energy transfer from one place to another. Thus, thermodynamics is defined as the study of equilibrium states of a system which has been subjected to some energy transformation. The main task of atmospheric thermodynamics is to interpret the average properties of macroscopic properties of a system in equilibrium, and related to proportionally slow movements, utilizing mathematical-physical concept (Bohren and Albrecht 1998; Tsonis 2002; Zdunkowski and Bott 2004; Curry and Webster 2005; North and Erukhimova 2009; Hantel 2013; Khvorostyanov and Curry 2014). Atmospheric thermodynamics deals with the transformations of the energy in a system and between the system and its environment. The system is a typical example of the matter. The equilibrium state of the system can be fully determined by a small number of properties such as pressure, temperature, and volume. These properties are known as state variables, or thermodynamic variables. It can be applied in many scientific disciplines, including physics, chemistry, and biology. Thermodynamics plays an important role in our quantitative understanding of atmospheric processes in a wide range, from the smallest cloud microphysics process to the global atmospheric circulation (Iribarne and Godson 1973). The purpose of this chapter is to introduce the basic elements and relationships that exist in the thermodynamics. We first discuss about the ideal gas equation and its application in dry air, water vapour, and moist air. Then a brief description of a thermodynamic system is given. The following section concentrates on the relationship between the mechanical work performed by the system and the heat that gets in the system, as expressed in the first law of thermodynamics. Then several sections follow, pertaining to apply previously mentioned in the atmosphere. Finally, in this section, we focused on the second law of thermodynamics and the concept of entropy, laws that constitute the basis for derivation of some important relations in the field of atmospheric science.