The change in the temperature of an air mass that does not involve the addition or removal of heat is called .

Latent heat

Explanation:Latent heat is the process whereby energy is absorbed or released by a substance such as ice blocks, during a change in its physical state that occurs without changing its temperature. Latent heat is normally expressed as the amount of heat (in units of joules or calories) per mole or unit mass of the substance undergoing a change of state.The latent heat associated with melting of a solid material or freezing a liquid is called the heat of fusion; while that which is associated with vaporizing a liquid or a solid or condensing a vapour is called the heat of vaporization. For example, during the melting of Ice cubes, the Ice cubes melts as their temperature rises. During melting, the ice absorbs latent heat, which is used to change the state of the water from ice to liquid water. While the ice is absorbing latent heat, its temperature is not changing. Another example, is when a pot of water is kept boiling, the temperature remains at 100 °C (212 °F) until the last drop evaporates, because all the heat being added to the liquid is absorbed as latent heat of vaporization and removed by the escaping of vapour molecules.