Rising Air Cools-Sinking Air Warms
8
m/s
494
m/s
502 m/s
502
m/s
494
m/s
Rising Expanding
Sinking Contracting
Rising air parcel expands because pressure decreases with altitude
Expansion requires that the molecules do work against surrounding air
This uses up some of their internal energy which results in their temperature decreasingAssuming no transfer of heat across parcel walls (adiabatic expansion), cooling rate is 10oC/km
Expansion requires that the molecules do work against surrounding air
This uses up some of their internal energy which results in their temperature decreasingAssuming no transfer of heat across parcel walls (adiabatic expansion), cooling rate is 10oC/km
10oC
20oC
no
heat transfer
Ahrens, Fig 5.2
502 m/s