What happens to the volume of a rising or sinking air parcel?

• Consider a parcel of air at 1000mb

• The parcel will exert 1000 mb of pressure to counteract the atmospheric pressure acting on the parcel

• Recall that Pressure = Force/Area

• If no energy is added or taken away from the parcel, then the force of the molecules bumping into the side of the parcel will be constant, i.e.,

• Force = Pressure x Area = const