By following such a rising or sinking air parcel we can write a Lagrangian moisture budget and calculate adiabatic temperature changes for air that is saturated (foggy or cloudy). A graphical description of this process can be represented as moist adiabats on a thermo diagram. Saturated rising air does not cool as rapidly with altitude as dry air. Thermo diagrams can also include isohume lines that relate humidity state to temperature and pressure.