El Nino - Southern Oscillation

“normal” or “neutral”

• Equatorial trade winds blow westward

• Water “piles up” in western Pacific Ocean

• Water is warmer in western Pacific Ocean

• Upwelling of colder water in eastern Pacific Ocean

• Normal precip patterns

What is the jet stream?

• Current of air flowing 150 to 300 mph

• High in troposphere (about 10 km)

• Over the boundary between 2 air masses.

• Usually blows from west to east.

• Aircraft can use or avoid a jet stream.

RETURN OPTIONS:   BASIC GRAPHICS MODE   |   LIMITED GRAPHICS MODE   |  

FULL GRAPHICS MODE

What causes the jet stream?

• The temperature difference between 2 air masses.

• The greater the temp. diff., the faster the jet stream.

• Seasons (temp. diff.) can cause jet stream to shift position. Also the ENSO.

El Nino

• Tradewinds slow and/or stop

• Warm water covers more of equator

• No upwelling in eastern Pacific Ocean (collapse of fishing industry in Peru)

• Global change in weather patterns

NOAA / PMEL / TAO Project Office / El Niño Theme Page What are La Niña, El Niño and Normal Conditions

in the tropical Pacific Ocean?

La Niña is characterized by unusually cold ocean temperatures in the equatorial Pacific. El Niño is characterized by unusually warm ocean temperatues in the Equatorial Pacific Ocean.

These are graphics of the Reynolds Sea Surface Temperature (SST) analysis from the National Center for Environmental Prediction (NCEP) for the entire Pacific Ocean (70N to 70S). Also see plots of the Sea Surface Temperature Anomalies (the amount that the temperature differs from the normal value for the month). Also available is a graph of sea surface temperature for the entire Pacific Ocean.

See What is La Nina?Go to the El Niño Theme Page oar.pmel.taogroup@noaa.gov Disclaimer | Privacy Policy

                                                                                                                                                    

                                El Niño effect during December through February.

La Nina

• Increased velocity of westward tradewinds

• Colder water along more of equator (eastern end)

• Global change in weather patterns

                                                                                                                                                                                  

La Niña effect during December through February.

                                                                                                                                                                                    

La Niña effect during June through August.

How to forecast the ENSO cycle?

Need info about SST, ocean temperatures at depth and winds.

Array of TAO/TRITON

• Approx 70 moorings w/ about 400 buoys

• Completed Dec 1994 after 10 years

• 17 ships on 83 cruises from 6 countries (multi-national)

• In Oct 1999, Japan assumed responsibility for western Pacific moorings (TRITON)

TAO/TRITON

• Tropical Atmosphere & Ocean

• Motivated by 1982-83 El Nino event

                                                                                               

Home | Project overview | Data display | Data delivery | El Niño & La Niña | Site map

    

TAO Project OfficeNOAA | Pacific Marine Environmental Laboratory

7600 Sand Point Way NE Seattle, WA 98115atlasrt@noaa.gov

Credits | Disclaimer |Privacy Policy

A warning to vandals

Moored Buoys of the Tropical Atmosphere-Ocean Array

   

                                                        

What is the Tropical Atmosphere-Ocean

Data from TAO/TRITON

• Wind velocity

• SST (sea surface temperatures)

• Air temp

• 10 sub-surface temp’s to depth of 500 meters

Put the TAO/TRITON data into a computer model

Now can forecast path of storm track

                                                          

Note that the location of the jetstream is influenced by the location of the convection, e.g. the main mean jetstream for La Niña starts to the left of the normal scenario. These are the teleconnections to our mid-latitude weather.

Benefits of accurate ENSO forecasts

(hopefully, with predictions up to one year)

Drought forecasts

• Preparation for wildfires

• Cultivation of drought-tolerant crops

• Plan food distribution in developing countries

Forecast of Excessive Precipitation

• Preparation for extremes: hurricanes, tornadoes, etc

• Preparation for local flooding: mudslides

• Mosquito control in malarial zones

• Planting of wet-tolerant crops

Forecast of change in ocean temperatures

• Predict profitable fishery sites

• Monitor health of coral reef ecosystems

Economic benefits from forecasts

• Adjust the production of weather-related goods: vehicles, clothing, shelter

• Adapt use of recreational facilities: skiing, snowboarding, boating

• Prepare for fluctuations in consumption of home-heating fuels

Review

What is ENSO?

ENSO

• The El Nino-Southern Oscillation Cycle• During normal years, equatorial trades

blow west• Ocean is 0.5 m higher & warmer in

western Pacific• Upwelling currents in eastern Pacific• 20 – 30 cm annual precip in San Diego• (8 to 12 inches)

b. Normal scenario

                                               

                   

What happens during El Nino?

a. El Niño

                                        

                         

What happens during La Nina?

                                                              

    

                Note that the location of the jetstream is influenced by the location of the convection, e.g. the main mean jetstream for La Niña starts to the left of the normal scenario. These are the teleconnections to our mid-latitude weather.

search NOAA

For more info about ENSO

The end