Adiabatic Processes, Lapse Rates and Rising Air
Extend understanding of your students by using the example of atmospheric thermodynamic processes. Use a video lecture that explains how adiabatic processes and lapse rates determine the stability of the atmosphere and in turn, influence cloud formation.
- In atmospheric sciences, the basic thermodynamic system studied is called the ‘air parcel’. As the name suggests, it is simply a volume of air with an imaginary boundary which separates it from the rest of the atmosphere.
- Vertical motion in the atmosphere is usually faster than the rate at which the air parcel can exchange heat with the surrounding air (environment).
- Therefore, most vertical motion in the atmosphere is approximately adiabatic. Using this approximation, we can estimate how much the air parcel cools as it rises in the atmosphere- known as the ‘atmospheric lapse rate’.
- Use the video, ‘Adiabatic Processes, Lapse Rates and Rising Air’ by Stephan Becker, Lehman College CUNY to explain the lapse rate in the atmosphere.
- Emphasize on how this is changed in the absence or presence of water vapour and thereby, affects condensation and cloud formation.
Video
Video by Stephan Becker, Lehman College CUNY