Case Study 2.1 - Climate Variability in the Equatorial Pacific
- Learn how to read two types of plots: a lat-lon contour plot, and a Hovmöller diagram.
- Be able to identify changes in tropical sea-surface temperature, precipitation, and pressure patterns over time.
- Explain how temperature and pressure anomalies affect the location of precipitation in the tropical Pacific.
- Introduce students to strategies for interpreting data that varies in both space and time.
- Use an inquiry approach to introduce students to the phenomena of climate variability in the tropical Pacific.
- Illustrate relationships between temperature, pressure, and precipitation.
Context for Use
Description and Teaching Materials
The data for students is in a PowerPoint file. Depending on the format of the class, students may access these data electronically, or you may wish to make color printouts for students to view in class. There is also a grayscale version of the data sheets. If printing out the grayscale versions for use in class, I highly recommended that each group of students have at least one color copy as well, if possible. There are three types of data: sea-surface temperature/wind, precipitation, and pressure. The pressure data are optional and will work best if used in a small class or with more advanced students. In a large class, with strict time constraints, it might be best to divide the students into groups of three to four. Have each group focus on either temperature or precipitation. The student handout posted here has questions about each type of data in Part 1. You may wish to provide students with the entire document or simply the subset of questions that their group will focus on. Part 2 contains questions for students to complete after a class discussion.
Case Study 2.1 Student Handout (Microsoft Word 39kB Feb18 15)
The following three documents combine the data and questions for each group.
Case Study 2.1 Student Handout - Precipitation (Microsoft Word 898kB Feb18 15)
Case Study 2.1 Student Handout - Pressure Anomalies (Microsoft Word 248kB Feb18 15)
Teaching Notes and Tips
Prior to the activity, students should have an idea how to read a contour plot, and be familiar with the term anomaly and how an anomaly is computed.
During class discussion after students have completed Part 1, it is helpful to organize the data using a table. The file available here contains a sample table and some suggested discussion prompts.
Case Study 2.1 Teaching Notes (Microsoft Word 2007 (.docx) 69kB May22 14)
The student handout may be used as an assessment. The two questions in Part 2 of the handout are designed specifically for use as a formative assessment. Are students able to articulate/summarize the group and class discussion regarding the effects of temperature and pressure on tropical precipitation? Can they describe the annual variability that occurs along the equator in terms temperature shifts in given locations?
The following document provides answers to the questions in the student handout:
Additionally, students may be presented with Case Study 2.2, which requires them to consider a new set of data in the North Atlantic.
References and Resources
Data contained in the PowerPoint for this activity comes from two sources:
NOAA TAO/TRITON Data Display (more info) and the NCEP NOMADS Server containing NCEP Reanalysis model output. This activity could be modified or expanded with additional data from these sites. Alternatively, more advanced students could be directed to access these data themselves.