Predicting an El Nino

What is an El Nino?

Task

In this task you will be part of an expert team.  Your team will be responsible for collecting data, organizing it in an appropriate graphic form, and analyzing it for the purpose of making El Nino predictions.  After making your prediction, you will summarize how you reached your conclusion and then share your findings with the scientific community.   Successful prediction of an El Nino could save millions of dollars and perhaps hundreds of lives.  

Section 1: Background

• NOAA’s El Nino theme page
• El Nino Impacts on the ocean
• Animation's of El Nino events
• Benefits of successful El Nino predictions.
• El Nino’s impact on sea surface height and temperature
• Interative Map Showing World Wide Impacts of El Nino
• BBC: El Nino Causes Weather Chaos
• El Nino's Reach
  

1. Describe normal ocean conditions in the tropical pacific (non El Nino years).  Be specific to sea surface temperatures (SST's), wind, and rain patterns.
2. What is the difference between El Niño and La Niña?
3. Why is predicting these cycles important?  (In other words what are the benefits of a successful prediction?
   
4. What are the possible impacts of weather on South American and Austrailia due to an El Niño cycle?   Due to a La Nina cycle?
5. What is the TAO network, and what is its purpose.
6. Look up the word"anomaly" and write a definition that makes sense to you.
   

Section 2: Collect Data

6. It's time to start gathering some sea surface temperature (SST)data, so that your team can begin the process of making an accurate prediction. You will be using a buoy located at 110 degrees West and 0 degrees North.  (see arrow to the right for this buoy's location)  Click the following link: current data for this buoy.  This link shows you the conditions in real time.  Look at the bottom picture, are temperatures right now above or below normal? If the anomalies are positive it means that it is warmer than normal. If they are negative it means they are colder than normal.

7. One day's temperatures does not tell us much.  We need more data.  To get data for recent weeks follow the instructions below.

• Right click on the data link above (on a mac, hold down the apple button) to get it to open in another window or tab
• Select the green button labeled time series plot.
• Under averaging select daily.
• Under data type make sure SST is checked, but nothing else.
• In the buoys check 0º N 110º W
• On the bottom select dates to give you the last 30 days
• Click "make plot" and draw the graph that comes up.

Section 3: Analysis

8. You will now create a graph that shows variance from the norm of the mean sea surface temperature for this month.  El Nino's are judged by how much warmer or colder they are from the normal mean tempature. Subtract each of the last 30 days temperatures from the mean temperature for this month (Sep=24.6° C).  This gives you the daily anomalies (find your month in the table above). Create a line graph just like the one above. Put the SST anomolies in for each of the last 30 days. When the anomoly is positive the data point goes above the line, when it is negative it goes below the line.  

Section 4: Conclusions

9. Are we currently in an El Nino Cycle, a La Nina Cycle, or normal conditions?  State your hypothesis and provide evidence to back up your hypothesis. To do this compare your anomalies to the historical anomaly graph seen here.  An El Nino is a sustained period with greater than +1 anomolies.  An La Nina is a sustained period with less than -1 anomolies. It may help you to know that the strongest El Nino years were 1982-83, 1997-98.  Weaker El Nino’s were recorded in 1986-87 and 2002-03. Finally, you may want to go back to the data link and gather more evidence. This may take the form of isotherm data, wind speed and direction, or average air temperatures.

10. Want to know if you are right?  Click here for the experts latest prediction on the likelihood of an El Nino/ La Nina in the next few months.   Assess yourself, how close was your prediction to theirs?

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