Determining Air Parcel Temperature: Rising air parcels and adiabatic cooling

  • consider a rising parcel of air -->>

  • As the parcel rises, it will adiabatically expand and cool (recall our discussion in chapter 5 about rising parcels of air)

  • adiabatic - a process where the parcel temperature changes due to an expansion or compression, no heat is added or taken away from the parcel

  • the parcel expands since the lower pressure outside allows the air molecules to push out on the parcel walls

  • since it takes energy for the parcel molecules to "push out" on the parcel walls, they use up some of their internal energy in the process.

  • therefore, the parcel also cools since temperature is proportional to molecular internal energy