Topic Guide: El Nino

In this activity you will form groups, conduct research into the El Nino phenomenon, and report back to your lab section in the form of a presentation. At the end of this activity you will find suggestions for the format of the presentation. You will use the data you investigate as evidence for your statements. Please use these suggestions and the “How to make a class presentation” as guidelines for your presentation.

Overview:

The El-Nino affects the weather in nearly every nation. It is interesting that a phenomenona that occur primarily in the equatorial region would have such widespread impacts. Not only are fisheries affected, but there are rainfall increases in some location and droughts in others. A great deal of research, including a lotof data acquisition, has been conducted and scientists now have some confidence that they understand the El-Nino and can predict it about a year in advance.

A phenomena related to the El-Nino (or ENSO), is the La-Nina, a period of colder than normal equatorial waters that follows El-Nino. These phenomena illustrate the importance of sea surface temperatures on the global weather patterns.

Key processes and concepts to review before beginning:

Global atmospheric circulation patterns
Ocean surface current patterns

Resources:

World Wide Web
Your textbook

After completing this investigation you should be able to:

Explain the El Nino phenomena
Predict the development of the El Nino
Understand the beneficial as well as negative effects of El Nino

You can go straight into exploring the data, but if you need more background information about paleoclimate, please review the websites that provide background information (found after the data section).

Background Information and Data:

It is important that you understand what the El Nino, which is sometimes referred to as ENSO (El Nino - Southern Oscillation), and La Nina cyclic phenomena are.

http://www.pmel.noaa.gov/toga-tao/el-nino-story.html

This site will help you answer the basic questions about El Nino. Be sure to notice how El Nino affects your Earth Summit country.

What is the El Nino phenomenon?
Why is the El Nino easier to pick out of SST Anomaly data, instead of just looking at the SST data?
What is La Nina?
How is La Nina different than El Nino?
What happens to upwelling and primary productivity during an El Nino event?

While patterns evident in the data you can use this table to keep track of the physical changes that occur as the El Nino and La Nina phenomena cycle.

Conditions	Trade Winds	SST	SSL	Primary productivity
Normal
El Nino
La Nina

http://www.pmel.noaa.gov/tao/elnino/la-nina-pacific.html

Carefully examine the three graphics, of sea surface temperatures (SST) for La Nina, normal conditions, and El Nino. Be sure that you also look at the SST Anomaly data, which you can display from the link at the right side of the page.

-->What are the differences between the sea surface temperatures for the three conditions?

Observe SST Anomalies for El-Nino at the Lamont Climate Data Server

<Link to SST Anomaly Data> Click on the map to get the the data display page. Study years between 1980 and 1998. See if you can identify the El Nino years. You can plot animations of the SST anomaly by entering the start month, and end month in the "Time" field (for example "Jan 1990 to dec 1990"). Click "Redraw" to get a new figure drawn, according to your time setting. Be sure to note the magnitude of anomalous tempurature rise in the region affected by El Nino.

Describe major changes in the pattern of SST occurring off the South American coast? Give temperatures and years of the El Nino.

Models of El-Nino:

Idealized ENSO Simulation

http://www.cdc.noaa.gov/~jjb/anim.html

This animation takes into account changes in sea surface temperature and height during El Nino/La Nina cycles. Be sure to identify the axes of the graph to understand what is happening in the animation.

You already know what happens to SST during an El Nino, but what happens to sea surface levels (SSL)?

http://winds.jpl.nasa.gov/images/winds_over_ocean2.gif

http://www.pmel.noaa.gov/tao/elnino/report/el-nino-report.html#part6

http://www.pmel.noaa.gov/tao/elnino/report/figure14.html

http://www.pmel.noaa.gov/tao/elnino/report/figure16.html

What is the relationship between the Trade Winds and El Nino? What affect do these winds have on sea surface height? Why is it that during non-El Nino years, the water off South America is cooler than during El Nino years?

http://www.esr.org/sfcurrents/sfc.html

http://lwf.ncdc.noaa.gov/oa/climate/elnino/elnino.html

-->Are we currently in an El Nino?

-->What are some of the global effects of El-Nino on precipitation?

The Lamont climate data library has other datasets pertinent to the study of El-Nino. For example, monthly global precipation data are available for the years 1971 to 1999. You can access these by going to the class "Earth Data" web page and scrolling down to the "Lamont Data direct links" entries. You can also go directly to the Lamont site and click on the "Maproom" link.. DO THIS.

More background information:

Please take some time to browse the links for information on the topic of El Nino. If you learn something new and interesting, please share it with the lab in your presentation.

http://podaac-www.jpl.nasa.gov/hot/el_nino/

http://www.pmel.noaa.gov/toga-tao/el-nino/nino-home.html

http://darwin.bio.uci.edu/~sustain/ENSO.html

http://topex-www.jpl.nasa.gov/science/el-nino.html

http://www.coaps.fsu.edu/lib/elninolinks/

http://www.atmos.washington.edu/gcg/RTN/rtnt.html

http://walrus.wr.usgs.gov/elnino/

http://geochange.er.usgs.gov/sw/changes/natural/elnino/

Presentation Framework

Your presentation should include a brief overview explaining the significance of El Nino. You should then choose as many of the following topics as is necessary to explain the concept. Choose topics that you think might be relevant to understanding the El Nino phenomena. Your presentation should include interesting findings from your investigations, backed up with data. You must use the physical data in your presentation.

You may choose from the following list of topics, or investigate a topic of your own. The topics in the list are examples of investigations that could be made using the data available at the URL’s listed above.

Data driven topics :

How does the El Nino phenomena develop?
What is the evidence that scientists use to confirm that this is occurring?
What are some of the parameters they measure?
What happens to upwelling and primary productivity during an El Nino event? Where are these effects most prominent?
What regions are most affected by El-Nino and how are they affected?

Overview type topics:

Why do you think scientists closely monitor the El Nino?
What are some of the hardships caused by El Nino?
What are the benefits of El Nino?
What is La Nina? How is it different than El Nino?