As an undergraduate Physics teacher, you can use this set of computer-based tools to help you in teaching the principle of thermodynamics and about thermodynamic processes.
A fundamental notion in Thermodynamics is a ‘Thermodynamic System’. A thermodynamic system is a part of the universe that is under study; the rest of the universe is considered the ‘environment’ for this system. The separation between the system and the environment may be real (like a wall) or imaginary. Every thermodynamic system has certain measurable quantities called state variables such as pressure, volume, temperature, density, internal energy, entropy, and enthalpy. In this lesson plan, students will learn about thermodynamics processes and their examples in the atmosphere that determine the vertical temperature structure of the atmosphere.
This lesson plan will also describe how the thermodynamic stability of the atmosphere changes and how adiabatic processes affect cloud formation, a component of climate. It also includes an interactive simulation tool to enable students to explore the different types of thermodynamic processes in a gaseous system. Thus, the use of this lesson plan allows you to integrate the teaching of a climate science topic with a core topic in Physics.
Image: A thermodynamic diagram showing the stability of the atmosphere based on the dry (Γd = 9.8 K km-1) and moist (Γm = 4.5 K km-1) adiabatic lapse rates (Created by Britt Seifert).
Use this lesson plan to help your students find answers to:
- What is a thermodynamic system?
- What are the thermodynamic state variables?
- Describe the different kinds of thermodynamic processes.
- Explain how atmospheric stability and cloud formation are affected by thermodynamic adiabatic processes.
Image: Vertical structure of the atmophere
About Lesson Plan
|Topic(s) in Discipline||Thermodynamics, Thermodynamic Systems, Thermodynamic Processes- Isothermic
Isobaric, Isovolumetric, and Adiabatic, Lapse Rates.
|Climate Topic||Climate and the Atmosphere|
|Access||Online, Offline, An interactive tool available in several languages|
|50 – 60 min|
A reading that introduces various thermodynamic processes and provides a few exercises to understand them.
|A video lecture that explains how adiabatic processes and lapse rates determine the stability of the atmosphere and in turn, influence cloud formation.|
|Simulation (20 min)||An interactive simulation to explore thermodynamic processes in a gaseous system. This tool is available in several languages.|
Here is a step-by-step guide to using this lesson plan in the classroom/laboratory. We have suggested these steps as a possible plan of action. You may customize the lesson plan according to your preferences and requirements.
Step 1: Topic introduction and discussion
- Use the reading, ‘First Law of Thermodynamics and some Simple Processes’ by OpenStaxCollege, BCCampus Open Education, to introduce your students to common thermodynamic processes like isobaric, isovolumetric (or isochoric), isothermal and adiabatic processes.
- Thermodynamic processes are representation of the change of the state variables of a system. They are usually plotted using any two state variables as the x and y axes.
- The most commonly used plot is the P-V diagram, where Pressure and Volume are the two axes. However, any two thermodynamic state variables can be used as axes in a ‘Thermodynamic diagram’.
- Use the examples given in text to enable your students to understand these processes and their variables better.
Step 2: Extend understanding using the example of atmospheric thermodynamic processes
- 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 to your students how this is changed in the absence or presence of water vapour and thereby, affects condensation and cloud formation.
Step 3: Conduct a classroom/laboratory activity
- Use the interactive PhET simulation, ‘Gas Properties’ by University of Colorado Boulder to enable your students to explore the different state variables for a given gaseous system. This tool is available in several languages.
- Instruct your students to use the simulation to create scenarios for different thermodynamic processes ie. Isothermic, isobaric, isovolumetric or adiabatic.
- Use the video micro-lecture, ‘Thermodynamics and P-V Diagrams’ by Paul Andersen, Bozeman Science as a guide for design and analysis of your customized classroom activity to explain thermodynamic processes involved in this simulation.