Cutting Edge > Topics > Climate Change > Teaching Activities > Rayleigh fractionation visualization

Rayleigh fractionation visualization

E. Christa Farmer
,
Hofstra University
The author is interested in feedback on this activity. Please send comments or questions to GEOECF@Hofstra.edu.
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This activity was selected for the On the Cutting Edge Reviewed Teaching Collection

This activity has received positive reviews in a peer review process involving five review categories. The five categories included in the process are

  • Scientific Accuracy
  • Alignment of Learning Goals, Activities, and Assessments
  • Pedagogic Effectiveness
  • Robustness (usability and dependability of all components)
  • Completeness of the ActivitySheet web page

For more information about the peer review process itself, please see http://serc.carleton.edu/NAGTWorkshops/review.html.


This page first made public: Aug 7, 2006

Summary

A MS Excel spreadsheet gives an account of Rayleigh fractionation, the progressive removal of the heavier oxygen isotope as a moist air parcel moves from the subtropics to the high latitudes. This exercise is useful for the interpretation of ice core paleoclimate records.

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Context

Audience

I use this resource in a laboratory on ice core paleoclimatology in an undergraduate paleoclimatology course for geology majors.

Skills and concepts that students must have mastered

Students must understand how to construct and manipulate formulas in MS Excel spreadsheet cells.

How the activity is situated in the course

I use this exercise as one of a series of laboratory exercises studying different paleoclimate proxies.

Goals

Content/concepts goals for this activity

The content goals for this exercise include understanding how Rayleigh fractionation controls the oxygen isotopic composition of ice cores, and how this process is affected by temperature changes. This is how the major ice core paleoclimate proxy works.

Higher order thinking skills goals for this activity

Higher order thinking skills goals for this exercise include numeracy, specifically the ability to visualize isotope fractionation.

Other skills goals for this activity

No other specific skills goals pertain to the current version of this exercise– modifications welcome!

Description of the activity/assignment

Students answer several questions about Rayleigh fractionation and the oxygen isotope composition of ice cores which require them to manipulate the values and equations in a MS Excel spreadsheet. This helps them to see how the oxygen isotope composition of ice cores changes with temperature in the high latitudes. Future iterations of the exercise should include a visualization of the Clausius-Clapeyron equation.

Determining whether students have met the goals

If the students can answer the numerical questions accurately, I figure they have grasped the mechanics of the spreadsheet. If they can answer the conceptual questions, I figure they have understood the operation of Rayleigh fractionation.

More information about assessment tools and techniques.

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Supporting references/URLs

The author is interested in feedback on this activity. Please send comments or questions to GEOECF@Hofstra.edu.

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