PSD's El Niño FAQ


 * How will El Niño impact a particular region of the world?
 * What are the predictions for El Niño?
 * What is the SOI (Southern Oscillation Index)?
 * When is the MEI updated? How can I get those numbers?
 * Can I use PSD plots and how do I acknowledge PSD?
 * What is the most recent SST/El Niño data available?
 * What is a good source of El Niño information for young people?
 * What is source of El Niño/La Niña information for adults?
 * How do I get climate data to look at El Niño myself.
 * What years are El Niño/La Niña years.
 * What is the difference between El Niño, ENSO and the Southern Oscillation?
 * Who are good contacts for reporters?
 * Where can I find other ENSO FAQs?


How will El Niño impact a particular region?

There has been a lot research investigating the effects of El Niño/Southern Oscillation on climate (temperature, rainfall, snowpack, climate extremes etc.) throughout the world. The research has been compiled at several web sites including Note that there are very few regions where the effects of El Niño/La Nina are consistent every year due to both the varying nature of El Niño and the inherent variance of the atmosphere/ocean system. The research is best utilized to indicate the probability of what the effects will be.

What are the predictions for El Niño?

Official predictions for El Niño are produced by the Climate Prediction Center. Unofficial forecasts based on different models and/or statistical techniques are also available at several locations.

When is the MEI updated? How can I get those numbers?

The MEI is generally updated by the 3rd workday of the month. If you are interested in obtaining the numbers used in the plot or want further information about how the index is derived, please contact Klaus Wolter klaus.wolter@noaa.gov

Can I use PSD plots and how do I acknowledge PSD?

You can use any PSD generated plot (either from a pregenerated figure or from an interactive program). We ask that you acknowledge the PSD in the publication. For example, "Image provided by the NOAA/OAR/ESRL PSD, Boulder Colorado from their Web site at http://www.esrl.noaa.gov/psd/".

What is the most recent SST/El Niño data?

NOAA's PMEL maintains a list of the most recent data/plots available.

What is a good source of El Niño information for young people?

See PSD's ENSO educational resource page.

What is source of information for adults?

There are numerous webpages that have information about El Niño. Some of the more "complete" websites that have links to data, research, predictions and so forth are the NOAA El Niño portal, the NOAA PMEL web page and the NOAA/CPC ENSO pages.

How do I get climate data to look at El Niño myself?

PMEL maintains a list of El Niño related data sources. Other sources of data include the National Centers for Environmental Information (basic station data on daily and monthly time scales), the (National Snow and Ice Data Center), the National Geophysical Data Center, National Oceanographic Data Center, National Center for Atmospheric Research Data Inventory and the meteorological FAQ.

What years are El Niño/La Niña years?

Definitions for what constitute an El Niño/La Niña event vary so there is not a definitive set of years. However, PSD (from Smith and Sardeshmukh and Kiladas and Diaz), CPC (ONI from the NOAA ERSST3) , and COAPS maintain a list of years used in their research. In addition, PSD makes available the MEI and the extended MEI index and CPC has a list of various atmospheric/ocean indexes from 1950 that can be used to determine ENSO years. NASA has a precipitation based ENSO timeseries called the ESPI. Some ENSO timeseries are available from 1870 at PSD's GCOS Timeseries webpage and more at PSD including the MEI.

What is the SOI (Southern Oscillation Index)?

It has been found that the cyclic warming and cooling of the eastern and central Pacific can be seen in the sea level pressure in the region. In particular, when the pressure measured at Darwin is compared with that measured at Tahiti, the differences between the two can be used to generate an "index" number. A positive number indicates La Niña (eastern tropical Pacific ocean cooling) and a negative number indicates El Niño (or ocean warming). Historical and recent values can be found at the Climate Prediction Center. PSD has a historical perspective on the SOI.

What is the difference between El Niño, ENSO and the Southern Oscillation?

El Niño refers to the oceanic component of the El Niño/Southern Oscillation system, the Southern Oscillation to the atmospheric component and ENSO to the coupled system. In practice, El Niño is sometimes used to refer to the entire system.

Who are good contacts for reporters?

The Office of Oceanic and Atmospheric Research has 2 media contacts:
Dane Konop (301) 713-2483
Barbara McGehan (Boulder, Colorado) (303) 497-6288

The main contacts for NOAA's department of public affairs are:
Lori Arguelles, Director
TEL: (202) 482-5647
FAX: (202) 219-8827

Tim Tomastik, Deputy Director
TEL: (202) 482-6090
FAX: (202) 482-3154

Where can I find other ENSO FAQs?