What does the term "adiabatic process" refer to?

An "adiabatic process" refers to a thermodynamic process in which there is no heat transfer between the system and its surroundings. This means that any changes in the internal energy of the system result solely from work done on or by the system, rather than from the addition or removal of heat.

In the context of atmospheric science, an adiabatic process often relates to how air parcels rise or descend in the atmosphere. As an air parcel rises, it expands and cools because it does work on the surrounding air, and since it does not exchange heat with its environment during this expansion, it is considered adiabatic.

Understanding this concept is crucial in meteorology, as it is fundamental to the formation of clouds and the dynamics of weather systems. In contrast, processes where heat is added or removed from a system, as suggested in the other choices, do not fit the definition of "adiabatic" because they involve heat transfer, which is not present in this type of process.